I had a look at your last minidump (dated 19.03.2008) and windbg says: "Probably caused by : ntkrnlpa.exe ( nt+a9ef2 )". At this point I would say to disable all non-Microsoft start-up items using Autoruns and uninstall any software that install kernel-mode drivers (antivirus, firewall, etc.) and see if the issue happens again. Anyway, I'm sure cluberti can give you an authoritative answer on this, just wait for him to have a look at this thread. EDIT: I forgot to welcome you to THE forum!