Mike's Blog

You need to tweak a registry setting in order to allow connecting to a windows share that is shared on a windows 2000 or xp machine from a Windows 7 machine. Here is the technet article that describes the registry setting that needs to be changed:

http://technet.microsoft.com/en-us/library/cc960646.aspx

Here is the relevant part from the post:

LmCompatibilityLevel

HKLM\SYSTEM\CurrentControlSet\Control\Lsa

Data type

Range

Default value

REG_DWORD

0–5

0

Description

Specifies the mode of authentication and session security to be used for network logons.

Value

Meaning

0

Clients use LM and NTLM authentication, but they never use NTLMv2 session security. Domain controllers accept LM, NTLM, and NTLMv2 authentication.

1

Clients use LM and NTLM authentication, and they use NTLMv2 session security if the server supports it. Domain controllers accept LM, NTLM, and NTLMv2 authentication.

2

Clients use only NTLM authentication, and they use NTLMv2 session security if the server supports it. Domain controller accepts LM, NTLM, and NTLMv2 authentication.

3

Clients use only NTLMv2 authentication, and they use NTLMv2 session security if the server supports it. Domain controllers accept LM, NTLM, and NTLMv2 authentication.

4

Clients use only NTLMv2 authentication, and they use NTLMv2 session security if the server supports it. Domain controller refuses LM authentication responses, but it accepts NTLM and NTLMv2.

5

Clients use only NTLMv2 authentication, and they use NTLMv2 session security if the server supports it. Domain controller refuses LM and NTLM authentication responses, but it accepts NTLMv2.