I did the "sfc/scanonce" and after the next reboot i was prompted for a windows 2000 CD and then it went on checking for about 15 minutes and ended without giving any messages!
There is something else I have noticed: restartings only happen when I set the TCP/IP to look for an IP Adrress automaticaly...and only when the network is active!
Here is the Hijackthis log:
Logfile of HijackThis v1.99.1
Scan saved at 19:04:29, on 16.08.2005
Platform: Windows 2000 SP4 (WinNT 5.00.2195)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)