I personally haven't used that exploit program so I can't comment for sure, but I'd be a little weary of it. I have a recommendation for you, for a tool that I have used and know that it works well and can be trusted. Download the Retina RPC DCOM Vulnerability Scanner from http://www.eeye.com - it will scan your network and report back to you the machines that are vulnerable.. The tool is available for free at this link: http://www.eeye.com/html/Research/Tools/RPCDCOM.html