How to Fix Windows XP That Crashed

1. Reboot your computer to make sure that the crash was not a one-time problem. Allow Windows XP to boot normally; if the operating system boots with no problems, then it's likely you won't crash again. If your computer has problems booting up, you may need to repair the installation.
2. Allow the computer to boot one more time before you begin the repair. But this time, select the 'Boot using last known good configuration' option from the boot menu. This will boot Windows XP using the settings from its last problem-free launch. Resetting the configurations that way may fix the problem that caused Windows XP to crash; if it doesn't, you'll need to repair your installation.
3. Place your Windows XP installation CD or recovery CD into your computer's CD or DVD drive if you are still unable to launch Windows without errors. Reboot the computer and choose to boot from the CD when prompted.
4. Allow the Windows XP installation program to start as normal. Press the 'Enter' key in order to start Windows XP setup; do not choose the option to launch the Windows XP Recovery Console.
5. Accept the licensing agreement when prompted. Wait while the Windows XP installation program searches for previously installed versions of the operating system.
6. Select the installation of Windows XP that you wish to repair from the list of detected installations, then press the 'R' key. This will start the repair process.
7. Wait while Windows copies necessary installation files to your hard drive, then allow the computer to reboot. Do not choose the option to boot from the installation CD, as the repair function will continue once the prompt to boot from the CD has passed.
8. Allow Windows XP to overwrite your installed operating system files, entering any information you are prompted for during the process. Though the installation program is installing new copies of your existing operating system files, many of your currently installed programs and settings will be preserved after the repair has completed.
9. Reactivate your copy of Windows XP if prompted to do so. Once the repair function has completed, you should be able to continue using Windows with no further problems.