If you are running a clean install, the problem with W2K,WinXP, and Win2003 will generally be drivers for cards, video, audio, NIC's, etc. If your audio or network connections are on the board itself, it could be these that have the problem in that they are not compatible.
The file you refer to (drvmain.sdb) is a database that contains compatibility problems with certain devices in Win2003. In setup, Win2003 tries to circumvent these problems with some substitutions. It is not always correct. Somewhere on your CD should be a collection of .sdb files that contain incompatibility problems. Viewing these might give you a clue.