I used these instructions to get my Windows 7 clients to connect to my Mac 10.4 server.
Early adopters of Microsoft’s new Vista operating system may notice that it will not connect to Samba share folders out of the box. This will be a bit of a pain for many enterprise customers. The technical reason is because Microsoft Vista’s default security policy is to only use NTLMv2 authentication. According to a Google search Samba doesn’t support this yet.
Update: Some readers have pointed out that NTLMv2 authentication is supported in Samba 3.0. However, this certainly wasn't an option to get this running in my instance.
To get Vista to work with Samba follow the simple instructions