Problem with "Denied Access" Message

[webekim]

I have an HP Pavilion dv 8000 Notebook computer running Windows XP in a stand-alone mode at my  home (no network).  Once a month, I run standard maintenance programs including the defrag program.  This month I attemped to access the defrag program, only to be receive the message "denied access". The message reads C:WINDOWS/system32\dfrg.msc. Can you help me to solve the problem?   Thanks!

[CarolinaPhotogu]

It sounds as if you tried to do your maintenance under a "guest" account instead of using your "Administrator" account.

I have tried to duplicate your problem and that is the only way that I was able to.

I hope this helps.

Pete 

[webekim]

Thanks, but that does not appear to be the problem.  I checked the administrator status and all  of the users on this computer are administrators, so that I should be able to access the security programs.  I checked programs installed on my computer and found one that does not belong there and which I was unable to delete:  HijackThis 1.99.1.  Am I a victim of a virus and how do I remove this program?

[CherylG]

HijackThis is an app used to troubleshoot problems with spyware/virus infections.Obviously another user of the machine has had problems and tried cleaning 'something' up. May even be the root if your problem.