Warning: This procedure is not supported by Microsoft and only describes how I managed to rename the groups in WSUS without having to create new ones. I cannot be held responsible if you break your WSUS DB even if you follow these instructions exactly.
WSUS 3.0 does not allow the rename of the groups trough user the interface. Although I understand some reasons why renaming a group could break your WSUS operation, being the most obvious that if you use Client Side Targeting and you rename the group the clients don’t get to be members of the old configured group name, since you have renamed it.
As far as I can remember this is the one unique situation where programmatically a computer is joined to a group by name. In all other cases the TargetGroupID field should be used to identify the group.
The standard procedure for renaming a group is to create a group with the new name, move the computers from the old group to the new one. If you have specific approvals for the old group you have to approve those updates on the newly created group.
The major problem is the moving of the computers. If the computers that are member of the old group aren’t all members of the exactly same groups then you can’t bulk move all computers and have to move one by one, or at least by computers that share the exact same groups or you will end up with all computers being member of all the groups of the computers involved.
So renaming a Computer Group in WSUS can be accomplished by connecting to the WSUS database, which in most cases is an Internal Windows Database and can be connected using the instructions in the “Using WSUS Views” MSDN Article.
Basically you will have to install Microsoft SQL Management Studio on the WSUS machine and connect using the string “\\.\pipe\MSSQL$MICROSOFT##SSEE\sql\query” in the server field. Authentication should be set to “Windows Authentication” and the user running the console should be member of machine “Administrators” group.
To rename a group, using Microsoft SQL Management Studio, navigate to Databases -> SUSDB -> Tables -> dbo.tbTargetGroup.
In this table you will find in the Name column your groups names. Using the SQL Mgmt Studio to Edit the rows you can now edit the Group names, by changing the desired field value.
After this change if you refresh the parent node in WSUS MMC Console Snap-In you will get an “Unexpected Error” in that pane hit “Reset Server Node” and the tree will reload showing the renamed Computer Group(s)
Remember: Use at your own risk…