>>35
Me was 98SE with the DOS bootloader hidden and CPU-draining bullshit added to the UI, along with system restore. It was less stable, and was not intended to replace 98SE for work-related installations, only for home users (almost like XP Home). Even Microsoft considers it a failed abortion.
2K was the first version of NT that was even more usable than its contemporary DOS-based Windows version. (The NT 4.0 UI was patterned after Windows 95, but wasn't as easy to use.) It was stable and no-nonsense. No DRM or activation bullshit, no superfluous UI trinkets, and it stayed out of your way. It's still a good choice for a stable work machine. Supports SMP (including dual-core chips like X2 and C2D), but does not support HT (which is not important unless you are using a HT-capable P4 - AMD and current Intel chips don't use it).
XP is 2K with DRM, fast user switching, the pathetic firewall, system restore (a.k.a. system slower-downer), remote assistance, and plenty of unnecessary UI changes added. So basically, it has higher system requirements than 2K for no *good* reason. However, for almost all systems these days, XP Pro brings out slightly better game performance than 2K Pro once you spend the hour that it takes to turn all the dumb shit off. Supports both SMP and HT.
VISTA stands for acquired immune deficiency syndrome. Abstinence is the only sure key to survival.