Konradr when you say it "recycles" back to the start screen do you mean it restarts and just goes back to that same start up in "blah blah blah" mode?
Windows XP is programmed to automatically restart upon a fatal system failure, unfortunately the means of fixing this is to go into your control panel and fix it, but since your system won't even start up you have 2 options.
1) Boot from an XP disk. If you have a windows XP disk you can insert it into your disk drive and when it restarts it will prompt you to repair your system, or boot from the disk. You should be able to repair without losing everything, and be aware of any warnings that let you know you are about to do so. Simply repairing your OS should do the trick, but it could be your boot config which means you'll need to run a command to fix it.
OPTION 2:
Booting into "safe mode":
When it starts to "recycle" press F8 about every 2 seconds until your computer goes into a new menu just like the "boot in last good configuration?" menu, only this time select safe mode.
If this works and you are able to get back to your desktop (it will look really blown up and high resolution, and you won't like it), follow the instructions found
HERE.