To do this, you will need to go to the Web.Config file on the Server (Important: Make a copy before making changes), this will be located here:
C:\Program Files (x86)\Autodesk\ADMS Professional 2011\Server\Web\Services
Open the Web.Config file in Notepad, then after < switches > add the following:
< add name="LogFileDeletesBooleanSwitch" value="1"/ >
