Windows 7 Users Can No Longer Connect to Shared Xserve Drive

We've had multiple computers (both PCs and Macs) setup to use a shared Xserve. All the sudden today the mapped network drives stopped working. I've tried using the "Map network drive" option on Windows 7 to add them manually again, but every time I enter the username/password it says it is not correct. I'm mapping the drive to Z and the folder to '\\10.10.10.77\shared' which is the Ethernet 1 of the Server followed by folder name on the Xserve that worked before. I'm confused what username and password it wants here because I've even reset the Xserve passwords and they still don't work and it says underneath that the Domain underneath is the name of the current PC user...

What's going on here? Am I using the correct Folder format and with the correct username and password? This is driving me crazy!