And therefore I formated and reinstalled Windows XP.
But during the installation of XP something went wrong, I think.
Because after that, my computer cannot install any Windows update anymore.
I only get an error message that says: the following updates did not install (which is none).
The second problem is that one partition (from the 2:nd harddrive) is always missing after startup.
So after every time I have started my computer I have to run PartitionMagic and choose "Convert" and give the partition a new label (which is the same drive letter for all times).
The third problem is that the Explorer is more unstable now and freezes from time to time and needs to shut down and restart. (Pretty annoying).
My computer is not working normal now.