Vista does kick up a "this program may have compatability problems" window,
however it is a mistake and shouldn't happen. If you ask it to resolve the
problem it will take you to the Bungie web-space where you can download a
new strings.dll and ....some other file.... which simply stop the error
message from appearing.
But if you dont mind the message you can just say "dont care, run the
program anyway" and it'll work perfectly.