AustrAlien

When the screen goes "blank", I am assuming it is black. I would be interested to know whether the mouse is still active at this time (can you see the mouse pointer and move it about, but nothing else at all functions, including the keyboard), as it is a very common situation.

If you google "xp black screen mouse", you will get a large number of results, with many and various solutions to the problem (actually to many and varied problems). I would suggest you try one of the links below (in my order of preference), if none of the following suggestions seem to lead anywhere.

*Remove everything that may be attached to the laptop .... including all usb devices. Try starting XP.
*See whether you can start Windows in Safe Mode, or does the same thing happen?
*Do you have an XP installation disk, that will boot up and get you to the Recovery Console; that will determine whether some of the suggested options are available to you.
*Consider what happened before the problem started, that may have caused it: Did you update Windows/update drivers? Did you have malware and run scans and remove malware? .... if you have an idea of what may have caused the problem, it may lead to employing the right fix to start with. Did you do a System Restore? Was your XP system misbehaving prior to the problem?

If you believe that no changes have been made recently that may have caused the problem, proceed in this order:
Check remove all external devices > check/repair HDD > repair/replace system files, with links below:

HBCD
UBCD4Win
aitechsolutions
http://support.microsoft.com/kb/314503
support.microsoft.com