This will keep your data safe and hopefully replace or repair any corrupt system files so that your system will boot correctly.
Repair Installation Instructions
· Insert your Windows XP CD in your CD-ROM and then Restart your computer.
· At the first post screen start tapping the Del key to enter System Bios
· Find the Advance Options or Boot Sequence screen.
· You will need to change the boot sequence so that the CDrom is first and the HD is second.
· Press F10 to Save and Exit and then press Enter to accept.
· The system will now reboot
· When the "Press any key to boot from CD" message is displayed on your screen, press a key to start your computer from the Windows XP CD.
· When you see the following message displayed on the Welcome to Setup screen, press ENTER
· To setup Windows XP now, press ENTER.
· At this point an option to press R to enter the Recovery Console is displayed. DO NOT SELECT THIS OPTION.
· On the Windows XP Licensing Agreement screen, press F8 to agree to the license agreement.
· Make sure that your current installation of Windows XP is selected and highlighted in the box, and then press the R key to repair Windows XP.
· Follow the instructions on the screen to complete Setup.
You can also go HERE
to read a step by step tutorial with screenshots.