Can't Log into SEPM after upgrade to 12.1.5 RU

After upgrading my SEPM to 12.1.5 RU I can't log into the SEPM.  I found this tech article (http://www.symantec.com/business/support/index?pag...) that explains my symptoms perfectly but I'm unable to modify my "Log on as a service Properties" becuase they are greyed out even though I'm,logged in as Administrator.

I'm running Win Server 2008 R2 standard ed.

Any help would be greatly appreciated!

Chris