SysInternals PortMon - "Error 6" Workaround

I was trying to use the SysInternals Portmon utility at work today, but it kept failing with the highly useful "Error 6" message. The error appeared when I tried to select a Windows XP PC for monitoring.

Searching around various forums, I noticed that some other people encountered this error, but I found no solution.

My own Workaround is this:
Run Portmon under an Administrator Account. Once.

I think that this tool needs to install some kind of 'hook' in the system so it can monitor the serial port. User accounts would not have the permissions to install this hook. After I ran this tool under the Administrator account one time, it ran under a less privileged account quite happily.

Hopefully this post will find its way through search engines to help some other techies. Please drop me a line if this helped you!