I am hearing that you can only install Vista once and if you upgrade memory etc.. you will need to buy a new license.

The only reason I switched from win2k to winxp was because win2k didn't support hyperhtreading well. Since the latest round of processors are simply dual core then I suspect that win2k will support them just fine. It has been along time since I even messed with win2k. Is it still supported somewhat? I am considering going back to it.