Have found the problem with my video card a Geforce 6600 (PCI-E)
After a while I got every first boot of my P4 system a blank screen, just after the windows logo comes up. Booting in safe mode (F8) was OK. I re-installed the drivers of Nvidia, even rolled back the old ones, but nothing helped :upset: . Even re-installed WinXP...no success....On Nvidia website they tell the problem is caused by AEC driver for a Logitech webcam !!! Haha...I don't believe this at all ! *** can a webcam driver causing this problem...bla, bla, that the Automatic Echo Cancellation stuff is the problem....funny story...
After i had a closer look to the vid-card I noticed that i had three bulging caps....Mmm, very suspecious...I measured ripple on voltage and that was not OK at all....
Replaced all three with 1000uF / 25 V types and the problem is solved.
All the best,