LKBEN10931: Howto deactivate SMB2 on Windows 2008, Vista or Windows 7


Symptom

SMB 1.0 is used by Windows XP, 2000 and 2003. SMB 2.0 is used by newer systems.

Cause

This is by design.

Solution

Windows 2008, Vista and Windows 7 use a more recent version of the SMB protocol. During connection, the protocol version is negociated. With some network card there are problems resulting in a slow network. (Broadcom NetExtrem and Intel Pro 1000 network cards are included)
As long as there is no update for this driver, you can disable the SMB2 feature or live with the slower connections till an update is available. e.g. the waiting on the user profile service can take 35 seconds.
To deactivate you create a new REG_DWORD in

HKLM\System\CurrentControlSet\Services\LanmanServer\Parameters

and set it to 0.

After rebooting the system the setting is activated. To disable it you set it to 1. My userlogon time changed from 40 seconds to 5 seconds.

You can use the following and save it as reg file to make it easier:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanServer\Parameters]
"SMB2"=dword:00000000


Disclaimer:

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About the Author

Author: Wim Peeters - Keskon GmbH & Co. KG

Wim Peeters is electronics engineer with an additional master in IT and over 30 years of experience, including time spent in support, development, consulting, training and database administration. Wim has worked with SQL Server since version 6.5. He has developed in C/C++, Java and C# on Windows and Linux. He writes knowledge base articles to solve IT problems and publishes them on the Lubby Knowledge Platform.