Underclock a Pentium/Overdrive/486

I'm wondering about underclocking a pentium. I've read about running Windows XP on a Pentium Overdrive underclocked to 8MHz with 20MB RAM. I was curious if anyone in here knew enough about the design of an early pentium or 486 to say if its possible to go lower, like 2MHz. For a joke I thought it would be fun to have an intel machine running XP or Vista at an Altair paced clock speed. XP took 30 minutes to boot at 8MHz, so I imagine a bare bones Vista would take a few hours at 2MHz, that is if Vista would even run on a Pentium... To me this is kind of like the project where someone booted Mac OS X on a 25MHz Centris 650 using a PPC emulator. Except most likely faster. : ) Maybe I'm just looking for something to carry me through the Alaskan winter. : ) Any thoughts? My first one is to set the jumpers as low as they would go and then start changing the onboard crystals/oscillators. Chances are the BIOS would still report 8MHz to windows and the screen shot wouldn't look as cool? I have already overclocked the Kenbak-1 500%, and underclocked it 800%. Time to move on to bigger and better things. Grant