If after turning on the power computer won't boot, this could be due to several reasons.
■ If the initial stage The boot screen shows the message Invalid system disk. Replace the disk, and then press any key and you can't do work at home, check if you have a floppy disk in your computer's drive. If a diskette is present in the drive, remove it and then press the Reset button on the front panel system block or turn off the computer's power and turn it on again.
There are few things more annoying than when your computer won't turn on. Restoring these faults can be tricky because many factors can be at the source of the problem. They may be caused by failure software and equipment.
Operating system boot does not start
In many cases, these may be the allowed minutes, although it is also possible that this may not start due to a serious problem that requires extensive technical knowledge. In these cases, we recommend that you take the computer to a computer service company.
■ Computer may not boot if the operating system boot process stops at any stage, press the Reset button on the front panel of the system unit or turn off the power of the computer and turn it on again, then press the F8 key at the initial stage of restarting the system. A menu will appear on the screen, in which you should select the Safe Mode item using the cursor keys in Windows 2000 / XP or by successively pressing the 3 and Enter keys in Windows 98 / Millennium Edition. After Windows finishes booting into failsafe mode, run a disk check. In Windows 98/Millennium Edition, to do this, select Start > Programs > Accessories > System Tools > Check Disk, and then click the Start button in the Disk Check program window that opens. In Windows 2000/XP, open the My Computer window, right-click on the icon of the drive on which Windows is installed (most often it is the C: drive), select Properties from the menu that opens. Click the mouse in the upper part of the window that appears on the screen, go to the Service tab, click the Run a check button, check the Automatically fix checkboxes system errors and how to set bad sectors, then click the Start button. Most likely, Windows will prompt you to perform a check at the next system boot, agree to this proposal by clicking on the Yes button. Restart your computer.
Press the power button again on the computer
Before restarting, make sure the computer is connected to a network or wall outlet. Then press the power button again.
Make sure all cables are connected
It is often worse if the computer does not turn on. But it may be because the laptop has no battery, or there is no cable without connection, and there is no current.All cables are connected. Is the power supply connected to the computer?
In the case of a portable computer, it checks that the charger is connected to the mains. It also often happens that the cable going from the outlet to charger, is free and does not reach power.
- One of the currents that connects the power supply to the plug or strip.
- One of the monitors that transmits the image of the computer to the screen.
If the computer did not boot, then after loading the operating system in safe mode(to select this mode, press the F8 key at the initial stage of Windows boot) in Windows Millennium Edition/2000/XP, you can use the System Restore utility. To do this, select Start > Programs > Accessories > System Tools > System Restore for Windows Millennium Edition/2000 or Start > All Programs > Accessories > System Tools > System Restore for Windows XP. In the right part of the System Restore window that opens, set the radio button to Restore your computer to an earlier point in time (Restore your computer to an earlier state) and click the Next button. On the left side of the next window, you will see a calendar image, in the table of which the dates in which Windows automatically created a “snapshot” of the system are highlighted in bold - it is to the state of one of these days that you can restore Windows using this program. These "snapshots" are called system restore points. You can switch months in the calendar by clicking on the buttons with the right and left arrows. After selecting the desired month, click on the date when the restore point you need was created. In the field to the right, you will see the time it was created and a short text comment. You can scroll through the list of restore points by clicking the right and left arrow buttons above the restore point descriptions. After selecting the desired restore point, click the Next button. The System Restore program will show you information about the selected restore point. Click the Next button to start system recovery. Within a few seconds, System Restore reads all the necessary information from the disk, after which the computer will restart. After the resuscitation process is completed, Windows will boot in normal mode with completely restored settings. System Restore does not mean that after restarting your computer you will lose the Lately documents or messages Email, however, programs installed after the date the restore point was created may not run, so you will need to reinstall them again.
If when you turn on the power of the computer from the system unit are heard sound signals, consisting of a series of long or short beeps (the image on the monitor screen may disappear), this means a hardware failure has occurred - most likely, computer won't boot because some part has failed in the computer. Contact a computer repair specialist.
There is no need to check if you turn on the light in the room and to make sure that there has not been a cut or that the fuses have blown. You can also check if the plug-in that the computer is connected to is working. Plug in the lamp mobile phone or another device to see if it works.
How to prioritize hard drive priority
Finally, just in case you're using one strip, try replacing it with another one to make sure it's working properly. It's as simple as pressing a button several times after turning on the computer. Prioritization hard drive on which is installed operating system. After saving the changes and restarting the computer for them to take effect.
Me, an engineer service center, we often hear complaints from customers that the computer does not start or does not boot. This is how various problems are described - from problems with switching on to disruption of the operating system boot. But to be more precise, “does not start” should be understood as not turning on, not initializing, or not working, while “does not boot” should mean problems with booting the system.
Start Safe or Safe Mode
Sometimes it just locks up while loading and the logo appears. Therefore, in modern computers you need to start safe mode by following other methods.
- It will show an option that will allow you to restore your computer.
- Just follow these steps: Press the left mouse button at the beginning.
- Click the right mouse button on the close symbol.
- Press the "Shift" button by clicking the left mouse button while restarting.
Consider, using examples of specific symptoms, why the computer does not start.
No response when pressing the power button
Causes
- There is no voltage in the mains, the electric cord is damaged or the power supply is out of order.
- Power button damaged.
- There is no electrical contact in the power connectors.
- The power control chip has failed.
- Damaged internal power supply (on laptops).
- Chipset failed.
- BIOS corrupted.
What to do?
- Make sure there is voltage in the mains. Check that the power supply is turned on and that the cable is securely connected to it. If possible, test the computer with a different power supply.
- To test the button, disconnect the wires from the Power Switch contacts (ON, PWR_ON, PC_ON) on the motherboard and short the contacts with a screwdriver. If the PC turns on normally, the button is to blame.
- reset BIOS settings removing the CMOS chip battery and shorting the socket pins. Or using the Clear CMOS jumper (button) (other names are CLRTC, CRTC, CL_CMOS, CCMOS).
The computer turns on (fans are running), but there is nothing on the screen
Hardware Issues: When a Component Stops Working
Inside, you can enter a menu with several options that will allow us to restore the computer. It is important to remember that if you do not have a backup, it is possible that you will lose all information. This option restores startup and restores it in case of any damage. This option can erase all information from the computer, use it with caution. This tool does not delete personal files. Restoring a system image. If you have a backup, this option allows you to restore it. It returns to the state it was in when one of those copies was made.
- Reset your computer.
- Restore the system.
Causes
- The processor is faulty or there are problems in its power system.
- The northbridge is out of order.
- Faulty strips, slots or RAM (RAM) power.
- "Flew" BIOS firmware.
What to do?
- Make sure that the processor is not damaged and that its cooling system is connected correctly.
- Check if the additional four-pin connector near the CPU power regulator is connected.
- Check the operation of the RAM sticks in different slots, try replacing them with known good ones.
- Reset BIOS settings.
Computer shuts down or restarts during startup
Damaged Power Supply: Symptom
This way we can determine if the source of the problem is in some unrelated components. A power surge or excessive dirt can damage this component and prevent the computer from turning on. If you have noticed any of the following symptoms lately, you may need to replace the font.
Random crashes: usually when the power supply starts showing errors before crashing. At the initial stage, you can turn off the computer when performing tasks that require more energy. Reboots or lockups can be an early symptom of a faulty power supply. It emits stronger or softer sounds than usual: when it emits strange sounds near the current socket, it is very likely that this is a failure in the power supply. Smell of burning: If your device emits a burning smell, it is definitely necessary to turn it off to avoid serious evils. When it comes from the power supply, it's time to replace it. The sound often sounds much louder or quieter than usual. . When a drive is damaged, it often emits a different kind of noise.
Causes
- Overheating of the processor or main elements of the motherboard.
- Failure (short circuit) of one of the computer devices.
- The voltage levels on the motherboard are out of range.
- BIOS problems.
What to do?
- Clean the cooling system of contaminants. Refresh the thermal paste layer on the processor.
- Turn off all devices that are not necessary to start the computer: peripherals, expansion cards (sound, network, etc.), optical drive, everything that is connected to USB (except for the keyboard), RAM (except for one bracket), hard drives, except for the system one. If the PC starts up, one of the disabled devices is to blame.
- Reset BIOS settings.
Operating system boot does not start
It is also possible that there is no sound. In short, if any of these two options occur, you need to replace it with a new one. In fact, if you didn't backup, you will lose the information it contains. One of these components can be predicted to fail. When they start to fail, they usually show up corrupted files or computer behavior becomes erratic.
If the computer turns on but does not display the graphics card image
Although some of them may appear when other components break. The idea is to indicate that it is failing. If you have more than one memory module installed, you can remove one of them. When he's not working graphics card very easy to distinguish.
Causes
- Systemic HDD out of order, incorrectly connected, or not receiving power.
- Chipset problems (southbridge).
- BIOS problems.
- MBR corruption or boot files operating system.
What to do?
- Make sure the hard drive is properly connected, operational, and receiving power. Check if it is defined in the BIOS and is visible when booting from other media.
- Reset BIOS settings.
If all else fails, and also if the problem with turning it on occurs on the laptop, contact the service.
Symptoms of a failed processor
In case this happens, if the monitor cable is connected and the screen is working properly, we will have to replace the graphics card. When the computer's brain fails, it's hard to tell it apart from a malfunction in the motherboard. Breaking this component is much rarer than those that occur on motherboards, but it's not enough to take it into account. The main signs of an idle processor are as follows.
What are the symptoms indicating damage to our motherboard?
- The computer appears to boot but does nothing.
- This may be a factory defect or the processor may be damaged by overheating.
About operating room problems Windows system XP, let's talk in more detail.
Why can the launch of Windows XP be disrupted?
There are many reasons why Win XP does not boot. These are damaged or missing boot files, changes in the registry, wrong settings boot.ini configuration file, MBR corruption (main boot record), and sometimes a combination of these factors. These problems most often occur due to the following:
What are the most common causes of motherboard failure?
And this can happen to any of the components, and they are all installed on the board. However, there are certain signals that give us indications that the malfunction may be similar to malfunctions in other peripherals.
- You see lines on the screen.
- Too slow ignition.
- The computer does not recognize external hard drives.
- Smell or burns on any part of the board.
- If you don't recognize some of the peripherals connected to it.
- virus activity, especially related to blocking the MBR and the Windows desktop, as well as due to failed attempts treatment of such viruses;
- errors when creating a configuration with loading of several operating systems;
- hard disk surface defects;
- power outages, due to which there is damage to Win files in the process of reading and writing.
To better understand the causes of Win XP boot failures, let's take a quick look at how this process goes.
Improper maintenance or excess dust can be fatal to anyone. Short circuit: This may be due to electrical voltage or static electricity away from the body during computer manipulation.
- Heat: Computer components are particularly sensitive to heat.
- Physical Damage: Produced by water or impact.
This excessive heating is mainly due to two reasons. The thermal paste dries out and doesn't work to pump heat from the CPU to the fan. Dust and lint obstruct ventilation and prevent heat from escaping. . Keep in mind that it is recommended to carry out preventive maintenance against heat and avoid it reducing system performance. Caring for these parts helps prolong the life of your equipment.
How to boot a computer running Windows XP
Before the system stages of turning on the PC - the receipt of the Power Good signal by the motherboard, the initialization of devices and the start of the execution of the BIOS code, we will not consider, since the problems at this stage are related to hardware. We will consider the start of Windows to be the execution of the MBR boot code, to which the BIOS transfers control. So.
Computer won't start at all
This morning you come to the office and the disaster, the computer does not start. And are you sure you disabled it correctly. Here are some basic checks and manipulations to identify and possibly fix the problem of a computer that won't turn on.
- Check the power cord.
- Check the electrical network.
- Turn on your computer if it's a laptop.
Failed to login
At startup, your computer displays the operating system logo, but you cannot access the desktop. Start your computer in safe mode. If you recently installed a new device, disable it. Here are the devices that can cause a conflict.
- The MBR finds the active partition in the table and transfers control to the boot code from its first sector (Boot Sector).
- Once executed, the boot sector code transfers control to the NTLDR file, the Windows XP bootloader.
- NTLDR puts the processor into 32-bit mode and checks to see if a hibernation image (hiberfil.sys file) has been saved to the hard drive. If there is such an image, it loads it; if not, it reads information from Boot.INI, the boot configuration file.
- If multiple copies of Win are installed on the computer, a menu is displayed from which the user can choose which system to boot.
Disk error or non-system disk
Memory card, additional hard drive, external hard drive, printer, new graphics card. If this message appears when you start your computer, the computer will look for the operating system elsewhere than on your hard drive.
What to do if the computer does not start
- Remove all media and removable media.
- Your hard drive may be damaged or defective.
The computer does not start: what causes it?
Check the cable connections and the condition of the keyboard, especially if a key is pressed or has a problem. If the screen is black, connect another monitor to make sure the monitor is not causing the problem. Remove equipment accessories. Your computer may have a compatibility issue. Disconnect and unplug all external connectors from the computer. Unplug the power cord and open the device. Check the connection of memory cards and chips. Overheating due to dust or use on a surface such as a sofa, blanket or lap. Problem with the motherboard, processor, memory or graphics. Operating system files are corrupted. In this case, relocation is required.
- Make sure the fans are running.
- A faulty or dirty fan can prevent your computer from starting.
- Dust your car regularly.
- Computer virus.
- Damaged hard drive.
- Defective video card.
- The device creates a conflict.
Disk error or non-system disk
Memory card, additional hard drive, external hard drive, printer, new graphics card. If this message appears when you start your computer, the computer will look for the operating system elsewhere than on your hard drive.
What to do if the computer does not start
- Remove all media and removable media.
- Your hard drive may be damaged or defective.
- After the system is selected, the ntdetect.com file is launched, which determines the hardware configuration of the current boot.
- Next, the files ntoskrnl.exe (Windows XP kernel) and Hal.dll (Hardware Abstraction Layer) are loaded - an intermediary between the PC hardware and the Win kernel.
- The last task of NTLDR is to launch the drivers marked as bootable in the registry and transfer control to the kernel code. At the same time, the equipment is initialized, the interrupt controller and the I / O system are turned on.
- The Windows XP kernel starts the session manager - Smss.exe, which creates the user environment, the graphics subsystem - Win32k.sys, the client-server execution subsystem Csrss.exe, the Win logon program - Winlogon.exe, the authentication service - Lsass.exe and Services.exe - Service Control Manager.
- This is followed by the launch of the welcome screen - LogonUI.exe and the user's Windows logon program - Userinit.exe.
- Next, the Explorer (Win shell) - Explorer.exe is launched, the desktop appears on the screen and the system goes into standby mode for user commands.
How to Repair Windows XP Boot
Win boot failure can occur at any of the stages listed. Knowing what follows what, it is easier to understand the reasons that disrupt the system startup.
Repairing the Master Boot Record (MBR)
If the MBR is damaged, it is interrupted at the very beginning, almost immediately after turning on the computer. It appears that the following message is displayed on the screen:
- Missing Operating System - the operating system was not found;
- Invalid Partition Table - invalid (defective) partition table;
- Error Loading Operating System - an error loading the operating system.
Or nothing is displayed.
If the MBR is damaged, both the boot code and the partition table can be damaged. To recover the MBR code, you need to start the computer with installation disk Windows XP and enter the recovery console. For this:
- put the installation disk in the drive and start downloading, when you see the message "Welcome to the installer", press the R key (restore);
- to work in the console, specify the Win XP serial number where you want to log in. If you have one system, press 1;
- enter the administrator password;
- enter the command fixmbr and press Enter - the boot code will be overwritten;
- to exit the console, enter the command exit.
The partition table cannot be fixed by Win's own tools. For this you have to use third party programs. One of these is the utility Test Disk , does an excellent job of this.
Boot Sector and NTLDR Boot Recovery
Boot sector code corruption has the same symptoms as MBR corruption, and error messages can be as follows:
- NTLDR is missing - NTLDR loader not found;
- A disk read error occurred - a disk read error occurred;
- NTLDR is compressed - NTLDR bootloader is compressed (not unzipped).
To solve this problem, you will again need the recovery console, where you will need to run the command fixboot.
The same messages may appear if there is no NTLDR bootloader in the root directory of Windows XP. A copy of this file, transferred from another computer under Windows control XP or from the installation disc.
Setting Boot Configuration (Boot.INI)
If configuration file Boot.INI contains errors, starting Win XP will also be impossible, since NTLDR will not know what to load and with what parameters. The system notifies you of this problem with the following messages:
- Check boot path and disk hardware - check the disk and the path to the boot partition;
- Could not read from selected boot disk - failed to read data from the selected boot disk;
- Windows could not start because of a computer disk hardware configuration problem - Windows startup failed due to disk configuration error.
The recovery console will again help you get out of the situation. Run the command: bootcfg /rebuild- it restores the standard boot.INI entries. In the course of her work sections of the hard disk are checked for installed copies of Win. If systems are found, entries about them are added to the configuration file, and the user can confirm or reject adding the system to the boot list. This way you can restore the launch of several copies of Windows at once.
Registry recovery
Another reason why XP won't boot is registry corruption, especially the System keys, which contain information about starting drivers, and Software, which contains boot control options.
To "roll back" these two partitions to the state at the time of system installation, start the recovery console and run the commands:
rename c:windowssystem32configsystemsystem.old
rename c:windowssystem32configsoftware software.old
copy c:windowsrepairsystem c:windowssystem32configsystem
copy c:windowsrepairsoftware c:windowssystem32configsoftware
In the same way, you can restore other Win registry keys: Defoult, Security and Sum.
Restoring Boot Files
You already know why the files responsible for starting Windows XP fail. Win in such cases loads almost to the end, but at some point it goes into a reboot or ends with a BSoD. So, error 0xC000021a (fatal system error) indicates the absence or damage of Winlogon.exe or Csrss.exe. Problems with other files may not be accompanied by messages, but only a black screen during the download process.
If you know exactly which files are missing, you can transfer them from another similar system or from the distribution disk - from the i386 folder. To do this, the computer also boots from the recovery console, where commands are executed to copy and unpack files from storage. Yes, the team expand d:i386userinit.ex_ c:windowssystem32 unzip and copy to a folder system32 file userinit.exe, where d: is the installation disk.
If it is not known which files are responsible, installing the system in recovery mode will help. System files will be overwritten, and programs, settings and user data will remain unchanged.
- Start your computer from the installation disk. When the “Welcome to the program…” window appears, continue the installation by pressing Enter.
- In the course of further work, the program will scan the disks and, if it finds a copy of Windows XP, will offer to restore. To do this, select it in the list and press "R".
- After the reboot, there will be several more stages where user participation will be required. Including entering the serial number.
- At the end of the operation, the files will be overwritten and if the reason why Windows did not boot was in them, the system will restore its work.
