My Dimension 8100 now starts up with the blue screen and NO_MORE_IRP_STACK_LOCATIONS. This is apparently a BIOS problem. I did upgrade my BIOS several weeks ago as advised by the XPSP2 instructions, using a BIOS upgrade from the Dell site.
I cannot restart my computer, in any mode.
Should I get my older BIOS back - if so from where? I am lost here.
Sounds like you are experiencing a problem with the operating system rather than the BIOS. If the BIOS was working Ok for several weeks after upgrading it then I doubt that's the problem. More than likely you are suffering from problems caused by the installation of Windows Service Pack 2. Chances are the Dell Moderator will move your posting to the Software - Windows Service Packs forum, but if he doesn't click here for a direct link to that forum.