I've checked all the files in this download and all the files that get installed to a clean xp installation with no av software, by connecting the drive as a slave to another pc with vipre and it comes up totally clean.

Your av may detect the keygen as a trojan - it is not.
The detection is only because it's designed behavior is like a virus - it sniffs your system, but that is only so it can generate the correct install/activation codes for you, or it is simply scare tactics.