Giga works extremely well on Win2k. I plan on building some dedicated giga PC\'s in the near future, and you can bet I\'ll be using Win2k. In my opinion, Windows XP is too new to be reliable, and has a bunch of extras that you don\'t need in a DAW or a Giga PC. You shouldn\'t have any major trouble on Win2K at all. Make sure you get the latest drivers from www.m-audio.com and the latest version of Giga.
I don\'t like Win2K for Giga, but I highly endorse the MOTU Delta1010 for Giga. I\'ve tested many different audio cards for latency, compatability, dependability, etc.... the Delta1010 scored as one of the best and is the #1 interface I use in my designs for analog only connections.
I use WinXP for Giga which runs quite well on my system. It appears that WinXP is used by more from many posts I\'ve read on multiple forums. I have WinXP running on quite a few machines and it is as stable as Win2K. Remember that XP is just an update to Win2K. It is not a complete rebuild of the kernel and addresses many problems that Win2K had. Also, Windows XP is already over a year old which in computer terms is not \'too new\'. It already has a service pack out which addresses most of the original release issues. I have Service Pack 1 installed and have not had any new problems with Giga.