Hi,
The registry variable:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\control\LSA\LMCompatibilityLevel
is used to set the minimum challenge/response algorithm.
The DWORD value can be: 0, 1, 2, 3, 4, 5.
Please know that the Mountain Lion OSX, Mavericks OSX and Yosemite OSX domian controllers does not accept LM, NTLM, LMv2, and NTLMv2 responses so if the Win 7 and Win 8.1 sends the LM, NTLM, LMv2, and NTLMv2 responses to MAC with these OSes it does not get responses back so the connection is unsuccessfull from the Win 7 or Win 8.1 side so the problem is in the Win 7 or Win 8.1 operating system which does not allow the connection to be made!
If you need this DWORD line in the registry you can stil connect from the MAC environment to the Win 7
or Win 8.1 shares!
But you can not connect from Win 7 or Win 8.1 environment to MAC OSX shares!
Best regards,
Gorazd.