Windows 7 dose not allow you to access any shared folders on NAS or Samba server by default. This is due to the change of security response protocal to LAN  manager authentication.

To temporarily solve this problem, you can follow the solution:

1) Run ‘secpol.msc’.

2) Navigate to ‘Security Settings/ Local Policies/ Security Options/ Network security: LAN Manager authentication level’, and change the value to ‘Send LM&NTLM – use NTLMv2 session security if negotiated’.

3) Run ‘regedit’.

4) Navigate to ‘HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\LmCompatibilityLevel’, then change the value to ‘1’.