I have two computers that I would like to be able to connect to one another if possible. One is being used as a music and video server with my Russound Cav6.6 whole house audio video system. The other is in the office.
The computer in the a/v room is running XP Pro SP3 and the office is Vista Ultimate 64bit. I am connected through a 2wire router and am hard wired and not wireless. What I want to be able to do is access music and videos off the office computer. I would also like to control and work with a program called Casa Tunes that the A/V computer has on it. The problem that I am having right now is that it recognizes the computers on the network but it won't let me in. I have been able to connect before but I can't seem to now. Is there something I might be missing? Thanks.

What is "it recognizes"? What is "it"? How do you mean "connect before but not now"?

If you mean to control/run the software on the XP from the Vista, I'm not sure you can unless the software allows for that (like MS-Office can, when properly installed on both, one being the "server").

Please be more specific. Not sure if I can help, but a better explanation may allow others to help...

As far as compatability goes, those Os versions should play nice; however since you have a workgroup environment you need to check a few things:

1) Both machines are on the same workgroup
2) Simple file sharing is OFF
3) you have a matching account with matching credentials on both computers (unless you dont mind authenticating everytime you connect from one to the other)

Research these things and see what you can do. If you are stuck feel free to ask again

Thanks