File corruption when using Windows Vista/Windows 7 or Windows Server 2008 with SMB2

Spanish version of this solution: http://www.caseware.com/support/caseknowledge/danos-en-archivo-al-utilizar-windows-vista-windows-7-o-windows-server-2008-con-smb2

French version of this solution: http://www.caseware.com/support/caseknowledge/corruption-de-fichier-lors-de-l2019utilisation-de

It is possible to create a Windows Registry key to disable SMB2 support on a workstation or server. Where these steps are performed depends on the configuration of the network share.

• On a Windows 2008 file server
• On a Citrix server which is installed on a Windows 2008 server
• On a Windows Vista or Windows 7 workstation acting as a file server
• On a Windows Vista or Windows 7 workstation where the file server may not be modified

On a Windows 2008 file server

In the scenario that a Windows 2008 server is hosting a client file for one or more Windows Vista or Windows 7 workstations, it is recommended these changes be performed on the server side, as they will only need to be made once. Before making any changes, the registry should be backed up.

Log onto the server and open the Windows Registry. To do so:

1. Click Start and in the run bar type enter Regedit
2. Locate and select the HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanmanServer\Parameters folder
3. Add a new REG_DWORD key:

1. Click Edit | New | DWORD (32-bit Value).
2. The new value will appear on the right, enter the name SMB2.
3. Double-click the new key to open the Edit DWORD (32-bit) Value dialog.
4. Ensure the Value data field is set to 0 and click OK.
5. Close the Windows Registry and reboot the server.
   

Note: To re-enable SMB2 at a future date, return to this key and set the value to 1.

 On a Citrix server which is installed on a Windows 2008 server

If Citrix is installed on a Windows 2008 server and is connecting to a Windows 2008 file server or Windows Vista or Windows 7 workstation hosting a client file, the registry key will need to be created on the Windows 2008 file server (or file-hosting Windows Vista or Windows 7 workstation). Follow the appropriate instructions to create the registry key.

On a Windows Vista or Windows 7 workstation acting as a file server

In the scenario that a Windows Vista or Windows 7 workstation is acting as a file server and hosting the client file for one or more Windows Vista or Windows 7 workstations or a Citrix Server running Working Papers, it is recommended these changes be performed on the host machine, as they will only need to be made once.

Log onto the host workstation and open the Windows Registry. To do so:

1. Click Start and in the run bar type enter Regedit
2. Locate and select the HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanmanServer\Parameters folder
3. Add a new REG_DWORD key:

1. Click Edit | New | DWORD (32-bit Value).
2. The new value will appear on the right, enter the name SMB2.
3. Double-click the new key to open the Edit DWORD (32-bit) Value dialog.
4. Ensure the Value data field is set to 0 and click OK.
5. Close the Windows Registry and reboot the server.
   

Note: To re-enable SMB2 at a future date, return to this key and set the value to 1.

On a Windows Vista or Windows 7 workstation where the file server may not be modified

In the event the file server is unavailable, or these changes may not be made on the server side, it is possible to disable SMB2 from the Windows Vista workstation(s) connecting to the client file. These steps must be performed on every Windows Vista or Windows 7 workstation.

Log onto the Windows Vista or Windows 7 workstation and open an Elevated Command Prompt. To do so:

1. Click Start | All Programs | Accessories.
2. Right-click on Command Prompt and select Run as Administrator.
3. The command prompt will open automatically.
4. Enter the following two commands exactly as shown. Note that after each equals sign (=) there is a space:

• sc config lanmanworkstation depend= bowser/mrxsmb10/nsi

• sc config mrxsmb20 start= disabled

Close the command prompt and reboot the workstation.

Note: To re-enable SMB2 at a future date, return to the Elevated Command Prompt by following these same instructions and enter the following two commands exactly as shown. Note, again, that after each equals sign there is a space:

• sc config lanmanworkstation depend= bowser/mrxsmb10/mrxsmb20/nsi

• sc config mrxsmb20 start= auto

Ensuring the stability of existing client files

Once these changes have been implemented and a reboot has been completed, it is recommended that any potentially affected shared files are repaired.