Ubuntu  is a free operating system (similar  to windows) that anyone can download  from the internet for free.  We offer to install, transfer documents and help customize setting for personal use.  Contact us for more information.

Quote from Ubuntu.com home page.
Ubuntu is a complete desktop Linux operating system, freely available with both community and professional support. The Ubuntu community is built on the ideas enshrined in the Ubuntu Manifesto: that software should be available free of charge, that software tools should be usable by people in their local language and despite any disabilities, and that people should have the freedom to customize and alter their software in whatever way they see fit.