1. As i recall, you only have Vista machines? I ask, in part, because Vista and XP use different terms for the same functions. My answer below uses only Vista terminology.
2. The vista computer which controls the disk with the files/folders you're sharing is the server. The computer requesting access to those files/folders is the client. Note that one computer can have both roles, a client AND server, if it shares some of its own resources while also requesting files/folder access from other computers.
3. In Vista there are two methods of file sharing:
- Password Protected
- Non password protected
It's the server which defines which method is applies. For each server, You define the method in Network and Sharing center by turning Password Protected Sharing on or off.
4. When Password Protected Sharing is on:
- A user must have accounts on server and any machine being used as the client
- Each account must have have identical userid and password defined
- By default, blank passwords (i.e. no password) is not allowed and cause "Access Denied" (this can be changed tho if you want)
- This is the most secure type of sharing tho you need make sure of those identical accounts for each account that wants shared access
5. When Password Protected Sharing is off:
- All client requests to the server use the Guest account for server access (is a special pre-defined account in Windows)
- So no account setup per user required
- Guest account does sometimes need some permissions set up, but can address that should you choose that route and still find problems