My computer recognize that I am the administrator



I have a problem with a few things I try to do on my computer and it does not recognize that I am the administrator.
The first thing was when I went to run a report on my computer for my
bit-defender Internet Securities 2010 it told me I don't have the privileges to run this, run as administrator. It also happened after I ran spybot S&D I went to fix all problems and told me I don't have the rights to perform this action as I am not the administrator.
I have only one user account on my computer I am always running as the administrator so I don't understand why I can't do it. Do I have some sort of virus or hijacker on my computer?