What trips most people up on this sort of thing, is that the user names don't match up.
If you want to share files between an XP and Vista system, BOTH systems need to have identical users for sharing. So if the XP system has a user account "John", the Vista system also needs to have a user account named "John" and the passwords need to be identical. Otherwise, you'll get that prompt asking for a username and password.
It makes very little sense, I know, but complaining to me about it won't do anything to fix it.
I'm stymied trying to fileshare using Windows Vista. It should be pretty simple, right? I click the "Share" button, select the Users I want, and click the button again.
Now, here is what actually happens when I try this: It says the folder has been successfully shared, but if I go back to properties for that folder (using the Pictures folder in this case), it clearly says that it is NOT shared. If I try to share it again, it says there was an error, and says that the containing folder is already shared. Sure enough, if I dig down a bit, the entire Users folder is apparently Shared. Why this should happen I have no idea, but it happens every time. In any case, I can't access any shared resources from any other computer. My PC shows up in the Workgroup, but trying to access it from another machine (XP SP3) it asks for my username and password, but when I enter them, it simply brings up the prompt again and again, never actually connecting.
I've tried reformatting and installing Vista from scratch to solve this, but there was no change. I can reproduce the exact same problem on the two Vista computers I have here. Help would be appreciated.

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