Google these two words -> BAD CAPS
The symptom is consistent with bad caps on any board or power supply. Or a very old, failing hard drive. But the odds are on bad caps.
The good news is the visual inspection has always verified the issue.
I have windows xp. when i have to boot the computer after being shut off it freezes on the windows xp scrolling task bar....i then have to reboot....always numerous times...like 8 or even 10 times before it will load....also the mouse will freeze after clicking on user to load preferences screeen. It will load windows with no problem if it does an auto reboot or if i manually reboot,,...any ideas..