Windows Installer Notice at start up

Everytime I turn the computer on, the Windows Installer box opens and gives the following message: "Preparing to install . . ." The next notice says: "Please wait while Windows installs BitDefender" It then says "The installer has insufficient privileges to access the directory C:\Program Files\Common Files\BitDefender\BitDefender Threat Scanner\av32bit\_000. The installation cannot continue. Log on as administrator or contact system administrator" Then 2 choices are offered - RETRY or CANCEL.
I then go through the cancel process 3 times and everything loads as before. My question is this: how do I get rid of this loop at each startup? I have already run ccleaner and malwarebytes. My computer runs much better but this message still exists.
I'm running a Dell Dimension 4600, WIndows XP Pro OS and have 1.5GB RAM. BitDefender has been my security suite for a few months now and this is not the first time things have gone funny on me. I'm getting annoyed with the whole thing at this point but don't want to quit after paying for it.
Thanks for your help.

 

Have you tried to re install bit defender?
HAve you tried to go to bit defender's web site and see if there is a patch or a posted update for the version you are using