OK, this one has me stumped.  I recently installed a BGF NVidia FX5500 and seem to have no problems with the card or drivers.  I also recently did a Windows update from the MS site (about 3 days prior to installing the video card).  

However, my Dim 8100 has recently (i.e. about 4 days AFTER I installed the video card) started to not reboot when I use Windows 2000 shutdown or restart functions.  It will actually go through the shutdown process and "appear" to fully load the bios (the status bar all the way to the right) but then it just hangs.  When it does this I am also unable to enter the bios setup (F2), which makes me think it might be a bios problem, but I am unsure.  I should add that it hangs on the Dell Bios screen.

I had originally thought the problem was the NVidia drivers since it seemed to work ok when I re-installed them.  However, after restarting properly twice it reverted back to not rebooting after the restart.

Once it hangs and I physically turn it off and wait a minute or so then turn it on again it 'usually' reboots just fine.  However, the odd time it will hang at the same spot even using this method. 

What bugs me, is the seemingly intermittent way that it hangs...why does it hang sometimes and not others?

Any possible suggestions would be appreciated prior to actually reinstalling windows or reformatting the drive.