These days with new operating systems and files, computers have many hidden files which normally do not delete when simply using the operating systems cleaning/maintenance utilities.  There are several commercial programs available that can adequately do the job for most computer users who desire privacy.  The good news is that most of these programs are free and we have them noted in our software section. A program like Webroots Window Washer when combined with the abilities of a free program like eraser can delete all of your internet tracks and get the files that would normally be missed, at about half the cost of buying another software title like one of the eliminator types.  Eraser can overwrite the free as well as slack space on your hard drive numerous times with x's, o's, and numbers making the recovery of deleted data pretty much impossible if you overwrite it 7 times or more.  The program will do this automatically for you if you set it to. Reformatting your hard drive is very far from secure, it still allows data to be recovered if the right utility is used.  The more you reformat the more you increase the security of the hard drive, but it's easier, faster and more secure to just use the right software and get the job done well. Encrypted folders or full disk encryption can be a very big plus if your computer gets hacked when not connected through our service, or if you physically loose it to theft or loss.  High security information should be stored in encrypted folders using passwords with a minimum length of 13 characters.  I've made note of some very capable free software in our software section that will do the job very nicely for you. You should check to see that your computer system has the latest operating system and browser updates frequently, and if your using Internet Explorer - don't.  Switch to a time proven privacy browser like Mozilla, it's free and it's excellent! Use a good anti-virus program as part of your ongoing computer activities, there are three very capable free ones noted in our software section that will protect you and update automatically.  No need to spend lot's of money for a titled program when you can get a proven one for free. Spyware and key loggers have proven to be a serious concern to every internet user.  A free program like Ad-Aware will remove spyware from your computer, and buying a program like spycop will pay for itself in the long run many times over, even if it only finds one key logger.