Yes I share files between Vista and W7.
These are the things I do to get file sharing to work (may not be the only method though)
1) Set the Windows workgroup name the same on both computers (any name you like)
2) Make sure you set up Windows so you have to logon Windows with a userid/password on both computers
3) Make sure you have a COMMON Windows userid/password on both computers. So if you are logged on to Windows with a userid of FRED and a password of ROONEY make sure your other PC at least has this userid / password combination registered as a Windows user. You dont have to be logged on as this, it just has to be registered.
4) Make sure you have a shared folder (at least one) on BOTH computers.
5) Make sure your firewall is not blocking access to the other computer.
After you have made all these change make sure you reboot both computers and logon to Windows with your userid/passwords.
After that you SHOULD be able to share files (fingers crossed).