I am trying to install ex. 2003 onto windows server 2003 SP2. Whenever I try to run forest prep it errors and says "Exchange server 2003 has known compatitbility issues with this version of windows" ??? The server that I am installing on is server 2003 w/SP2 and has had all updates installed? The server WAY exeeds the hardware specs? Any idea? Thanks guys.

You can ignore it while installation & it wouldnt give you any problem. This would be because of Windows 2003 SP2 was not released when Exchange 2003 was!!! But make sure that you apply SP2 of Exchange 2003 after installation and it should be fine.