From the FWIW department…
I have GnuPG 1.4.9 (downloaded the binary from the GnuPG.org site) running on a Win7 RC1 test laptop. I did install it, and GPGshell, in a XP SP3 compatibility mode. Both Thunderbird email and Enigmail are also running on the Win7 RC1 machine. I installed both of those in a Vista SP1 compatibility mode.