Uncle DaveO has given some good advice. Certain trojans are good at blocking Symantec functions. There are a number of free on line virus checkers. Try a few of them. If D is a data drive, look to see why it's so full. If D is a data drive, I commend you. It's a good idea. Many say it's unnecessary with XP. They only need to be wrong once in a million times for that one to be you.