Vista cannot authenticate when trying to attach to a file share (SMB) on our old 10.2 Mac Xserve. Fixing the problem involves weakening the security of Vista file sharing, but we're all friends here behind the firewall, right?
I stole these instructions from z3r010 on vistax64.com:
1. Open the Start Menu.
2. In the white line (Start Search) area, type regedit and press Enter.
3. Click Continue for UAC prompt.
4. In regedit, go to:-HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlLsa
5. In the right pane, right click LmCompatibilityLevel and click Modify.
NOTE: If it doesn't already exist, create a DWORD value named LmCompatibilityLevel
6. Set the value to 1
*UPDATE 8-25-2009 – I just had this same problem in Windows 7 and this solution fixed it. -Kris-