Vista can't connect to some old SMB shares (ie Lacie appliances, Samba shares)
- Start -> run -> secpol.msc
- Local Policies -> Security Options -> Network Security: LAN Manager Authentication
- Change NTVLM2 responses only to LM and NTLM - use NTLMV2 session security if negotiated
If you are stuck with a Vista Home, there is no secpol.msc. Instead:
- Start -> Run -> regedit
- navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
- for LmCompatibilityLevel, change the '3' to a '1'
- Rebooting might be necessary at this point.
Note that if this registry key doesn't exist, you should be able to create it.