When an engine is taken offline during the cleanup process of a scan engine update, a time-out may occur. When this occurs, the GetEngineFiles.exe process incorrectly deletes some files on a computer that is running Microsoft Forefront Security for SharePoint. Some files are deleted from the root drive instead of from the engine directory itself.
To resolve this issue, install Forefront Security for
SharePoint with Service Pack 3 (SP3).
For more information about Forefront Security for SharePoint SP3, click the following article number to view the article in the Microsoft Knowledge Base:
Description of Forefront Security for SharePoint with Service Pack 3
has confirmed that this is a problem in the Microsoft products that are listed
in the "Applies to" section.