So, for troubleshooting purposes, mostly in an environment that has mixes operating systems, you might want to consider disabling SMB 2.0. You need to do so on both the “client” and the “server” operating systems. To disable SMB 2.0 for Windows Vista or Windows Server 2008 systems that are the “client” systems run the following commands:

sc config lanmanworkstation depend= bowser/mrxsmb10/nsi
sc config mrxsmb20 start= disabled

Note there’s an extra ” ” (space) after the “=” sign.

To enable back SMB 2.0 for Windows Vista or Windows Server 2008 systems that are the “client” systems run the following commands:

sc config lanmanworkstation depend= bowser/mrxsmb10/mrxsmb20/nsi
sc config mrxsmb20 start= auto

Again, note there’s an extra ” ” (space) after the “=” sign.

In order to disable SMB 2.0 on the server-side computer, follow these steps:

Warning!

This document contains instructions for editing the registry. If you make any error while editing the registry, you can potentially cause Windows to fail or be unable to boot, requiring you to reinstall Windows. Edit the registry at your own risk. Always back up the registry before making any changes. If you do not feel comfortable editing the registry, do not attempt these instructions. Instead, seek the help of a trained computer specialist.

1. Run “regedit” on Windows Server 2008 based computer.
2. Expand and locate the sub tree as follows.

HKLM\System\CurrentControlSet\Services\LanmanServer\Parameters

3. Add a new REG_DWORD key with the name of “Smb2″ (without quotation mark)

Value name: Smb2
Value type: REG_DWORD
0 = disabled
1 = enabled

4. Set the value to 0 to disable SMB 2.0, or set it to 1 to re-enable SMB 2.0.
5. Reboot the server.

Posted by: andy