I have no disks and the buyer probably has tons. He works for a computer department for the military.

What folders other than photos, documents should I delete? Like if I applied for anything anywhere my credit card number and such would be on, where would I look to delete?

Somehow or other, I downloaded something called PC Registry Cleaner onto my computer, to fix a problem. Of course, they said it was "free" so I’m a sucker, and now they want my credit card number before they will exit from my computer. It shows up every time I go to my Yahoo page and it is really ticking me off! If I give them my credit card number (they want security code, too) how do I know I won’t be ripped off? Buyer beware! (Who can I report this VERY unethical behavior to, and get quick results?)

The credit card number I use online was stolen and now I am afraid to check my bank acct or anything from my computer. How can I make my computer safe and secure again?