These tips work on Snap Servers and NAS devices that say they are NOT Vista, 7 and 8 capable and XP workstations that will not connect.
When connecting Vista, 7 or 8 to XP, if you have problems, make sure the time is correct on both machines
On the Vista, 7 or 8 Computer
select Administrative Tools->Local Security Policy.
Select Local Policies->Security Options->Network security->LAN Manager authentication level.
Select this and use the drop down to change it to:
Use the setting “Send LM & NTLM – use NTLM v.2 if negotiated”
If you go to the UNC Path \\yourcomputer, you will have to use the username:
thecomputeryouareconnectingtoname\usernameonthatcomputer then enter your password.