Hi cracked,
Going to WIN2K wouldn`t be a very good idea as long as you have XP Pro .. they are the same .. and Yes, win2k should work on NTFS file system ...
I read your problem with explorer.exe (sorry, but i couldn`t figure that out) .. maybe it was a corrupted file ...
Anyway, I would suggest that you format your HDD and reinstall WinXP, give it another chance while we are on weekend.. disable the flashy colors by switching to classic windows and start menu ... if it still gives you hiccups .. then go for win2k .. that what would i do

..
About ccompatibility, mmm, some programs will work some will not .. some will work fine, some will give you headaches ... you`d be lucky if your software maker released a patch for win2k or XP ... so check their sites ...
Good luck dude
Regards