Hello. My name is Michael. I can help you with your question.
"Not in the most legal way". I hear ya. Everything has a price. I know.
What operating system is on it now?
Your approach is the best one. The only way to be sure is a reset. If it came with Windows, and you just want to put Windows back on it, you should be able to use the built in recovery.... Click "Start" and open "All Programs". Select "Recovery Manager", then click "Recovery Manager" again. Click on "System Recovery" at the bottom of the left hand column. Follow the prompts to restore your computer to factory settings. That's definitely the easiest way.