If I have my windows kernels correct, win2000 and XP are both built on the NT kernel. Xp is of course the newer version tho. Based on my experience, XP is the better of the two, but I had to change the menus and visual components back to "classic" windows just for them to be bearable. Do you absolutely have to run windows? If not, you should try out a Linux Distro. Ubuntu or Fedora Core perhaps.