OK Folks - I'll add MORE to the mix: I do PC tech support as my profession. My system (Win98) (128MB ram swapped), Client1 - Win NT4, Client2 - Win95 then 98 then new mobo/ram - are all having a freeze problem.
System simply stops - no errors - no determinate time (except that a hard disk access may be key - personal observation). Mouse - no action. Keyboard - no action (can't toggle LED's or three finger it). Turn off or hard reset. I recently swapped ram - still happens. Client 2 had the problem (w/ me at the kbd) before we upgraded his mobo/ram. After the upgrade - it still happened (yes we removed all old systemboard devices and let the OS redetect for the new one - D.Manager was happy - no yellow or red lines - the system runs fine except for this freeze.) I noticed a change after I installed a version 2 (beta) of the AOL/Netscape Instant Messenter. Client 1 uses full AOL. Client 2 has not touched AOL.
I'm searching everywhere on this one. I did the SFC on my system the other night - updated many DLL's. Has fozen since. Shortly I will try a Win98 reinstall ontop of itself but for me it might only lock up twice per week - so it will take a while to be able to pin it down.

Jim Williamson
...the Computer Lab