MarvOne,
This problem could be for a number of reasons. It could be due to a new hardware installation, new/old software or driver issues, or even loose cables inside your PC. Most likely, your issue has resulted from an error with XP's boot configuration files. (files needed for Windows to boot)
So let's start with fixing those, as well as all of XP's system files.
Insert your XP CD into your CD-ROM drive as soon as you power it on. If you get it in time, you'll see the press any key to boot from CD... message, if you do then press any key. If you don't get this message, reboot your computer. If again you don't see this message, we'll have to change some settings, but I'm confident you'll see it.
From this point, your computer will boot from the XP CD. When the boot has completed, you will be presented with a Windows Setup Welcome screen. You should have 3 options, one of which is to press "R" for the recovery console, please do this. Depending on the exact version of XP, you may or may not be presented with a message to enter the Admin password, if so proceed accordingly. When finished logging in, you should finally arrive at the recovery console, which is nothing more than the C:/prompt.
Once you've reached the recovery console, I want you to type the following command: sfc /scannow. This will tell the computer to copy all of the system files from the CD to your hard drive, providing you with fresh copies of all of XP's system files. When it's finished, take out the CD and reboot your computer. If this doesn't help, or you have another issue, repost.
Note: Once you reach Windows, I want you to visit the Windows Update page because although you have new system files, they are old and outdated. They must be replaced with current versions.
Note: The forum moderator will probably move this post to the correct forum location. If you repost or post another issue, please do so in the correct forum.
J_
