If a computer group is no longer required, you can delete it.
When you delete a computer group, the processing rule groups
associated with the computer group are no longer applied to the
computers in the computer group.
To delete a computer group:
Expand Microsoft Operations Manager (default) in the
left pane.
Expand Rules in the left pane.
Click Computer Groups in the left pane.
In the right pane, click the computer group that you want to
delete.