Doesn't work? Try the steps below:

For non-enterprises versions (example: Windows 7 Home Edtion):

1. Execute the  regedit
2. HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
3. Alterar LmCompatibilityLevel para 0x01

For enterprises versions (example: Windows 7 Enterprise Edition):

Execute (as administrator) on Run windows (Use the button  and "r" (WINKEY + R)) the command cmd do:

1. On the prompt windows execute "gpedit.msc".
2. Go to "\Local Computer Policy\Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options".
3. Change the "Security Setting" from "Network security: Lan Manager authentication level" to "Send LM & NTLM responses" or "Send LM & NTLM - use NTLMv2 session security if negotiated" as see in the picture.
4. Close the application.
5. Execute "gpupdate" to enforce the new police.
6. Close the prompt windows.