В доках к AVZ красным написано по поводу осторожной работы в серверных осях.
Народ не раз попадал.
Иногда вот это помогает -
To resolve this issue, delete the following registry subkey and then rebuild the policy:
To do this, follow these steps.
Note When you follow these steps, you delete the local policy. You must rebuild the local policy.
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows
Delete the local policy registry subkey. To do this, follow these steps:
Click Start, click Run, type regedit, and then click OK.
In Registry Editor, locate and then click the following subkey:
On the Edit menu, click Delete.
Click Yes to confirm that you want to delete the subkey.
Quit Registry Editor
Rebuild a new local policy store. To do this, follow this step:
Click Start, click Run, type regsvr32 polstore.dll, and then click OK.