Personal Use Vs. Non-Personal Use?

Interested at starting up a computer repair business, and have a question about virus/spyware removal software. I understand that a free license means you can do anything you want with it, as long as its personal and non-profit. Are there any softwares out that someone may recommend that are available for commercial/profit use. Also, how can I get permission for commercial use likes companies like BB and CC have, given I have little startup money for a serious license purchase(s). I don't want a visit to the courtroom courtesy of the BSA. Thanks.

-James