I have posted this in the Autodesk forum with no response, hopefully it will get more exposure and a solution here....thanks.

"Cannot update some system component now. Please root and try again."

I've been getting the above message when I try to install Revit Arch or MEP 2010 or 2011 on my XPsp3 machine. I've tried reinstalling all of the .Net components, I've tried switching to an Admin user even though I do have admin rights, I've tried tweaking the setup.ini file as suggested in another thread, I've disabled antivirus, I've restarted in diagnostic mode but nothing works. I am able to install 2009 versions but nothing more recent. Any help would be appreciated.