How to Recover Windows XP Without a Recovery Disc
The Microsoft Windows XP operating system can become unbootable in cases such as user-caused errors, application conflicts, driver conflicts and attacks by malware, including trojans and viruses. If you can no longer boot into Windows XP to repair the operating system, you can use the product installation disk as a recovery disk to bypass the failed operating system and boot to a recovery console. However, you can also recover Windows XP without a recovery disk or product installation disk by booting into safe mode and using the built-in system restore utility to reverse the damage done to the operating system.
Turn off the computer you want to recover. Restart the computer, pressing the "F8" key after you start the computer but before Windows starts to load. The computer will display boot options, including safe mode.
Use the arrow keys to navigate to and highlight safe mode. Press the "Enter" key to boot the computer into safe mode.
Click the "Start" button in the safe mode environment, and then click "Help and Support" to open the Help and Support page.
Click "Performance and Maintenance" on the Help and Support page, then click "Using System Restore to undo changes."
Click "Run the System Restore Wizard." This starts the wizard. Select a restore point from the list of restore points in the wizard, and then click the "Next" button.
Follow the prompts in the wizard. The wizard will roll back the system to a known good states, reversing the damage and restoring the system to a working condition. The computer will restart after roll back to complete the process.