Changing your account to an administrator is well discussed. But malware often stops use of msconfig and the task manager. Grif writes more at http://forums.cnet.com/5208-6142_102-0.html?messageID=3105025
In closing, you may want to choose a forum about your issue. Msconfig would not be a Dell problem.
I am using windows XP and, I have a Dell Dimension 8400 and I think someone has done something to it because after I put it in the shop, I cannot run a misconfig; My system does not recognize me as the system administer. Please help me.