What and How should I delete information from computer before selling it?

A few months ago I purchased a new laptop. I don't want my desktop anymore so I will either sell or give it away. What all should I remove or delete from the desktop before I sell/give away so that my personal information is gone?What and How should I delete information from computer before selling it?If you have the disk that came with it reformat/reload windows. That's about the only way to make sure all your private data is gone.What and How should I delete information from computer before selling it?Yeah,Reinstall Windows.