windows xp bootup loops?

That's normaly caused by some missing or corrupted system files. Another possible cause could be faulty RAM.

With the computer OFF, disconnect the power cord, posh the power button for a second to discharge all capacitors, and open the case.

This step MUST be done EVERY TIME you want to connect or disconnect anything inside the case. Failure to do so can cause fatal damage to the computer.

REMOVE all the RAM sticks.
Put back only one of them.
Close the case and try to boot.
If the boot faills as before, try with another stick.

If you can boot normaly, you have some faulty RAM. Put back the other sticks one at the time untill the problem comes back.
The last stick you put in IS DEFECTIVE and must be discarted and replaced.

If all your RAM is correct, your installation is corrupted.

You need to backup all your user files. It's also good to get the installers or install CD/DVD for all your applications and drivers.
For that task, using a live Linux CD/DVD is of great help.

From another computer, download the iso file for any distribution and burn it to a CD-R or DVD-R if it's to large for a CD. If your BIOS support booting from an USB device, you can make a bootable USB key and use it.

The Linux environment will allow you to copy all your files that are on your primary drive to some other location, like an external drive.
If you have more than a single drive, the files located on the other drives are safe.

Take note that logn term support and security updated for Windows XP will be terminated shortly. This means that there will be no more security updates. Windows update will for ever return NO update. Eventualy, you'll become unable to update your applications. It will be increasingly difficult to get new compatible applications, just as you can no longer find non-obsolete applications that can run on Windows 98...

If you REALY have no other choice, reinstall Windows XP. Reinstall your drivers and applications. Restore your files. Reconstruct any personalisation to your liking.

A much beter solution: install Windows 7 or Linux.
If you install Windows 7, ALL the files from Windows XP and the user profiles will be found in the Windows.old folder.

Electro
January 2014