My two Vista 64-bit machines can see each other (and my router) on the network - one is wired and one is wireless. However they cannot see my (wired) 32-bit computer nor my wireless XP computer. I have SP3 on the XP computer. I was able to see the XP computer until I did a router reset to resolve an internet access issue. Seeing the Vista 32-bit computer (SP2) was an issue even before the router reset. I've read several other posting about similar issues, but have not seen one where a Vista64-bit machine cannot see a Vista 32-bit machine. One 64-bit machine is SP2, one is SP1 (because SP2 installation keeps cancelling].

Additional information: All machines are in the same Workgroup. On the 32-bit Vista machine Network Sharing options (Network discovery, FIle sharing, public folder sharing, and printer sharing) are all ON. Also, the 32-bit Vista machine can see the 64-bit machines and router on the network (but not the XP machine).