Windows help needed

hey guys i'm building a pc

and i was wondering how to install windows on a pc when i thought if you guys could tell me or if it comes pre installed 

any way thanks

If you are building it yourself, you will need to buy a copy of Windows (7/8) and install it to your computer. If you have never done it before, there are many guides, but it will only come with the computer if it is pre-built.

Newegg did a video on this here -

Look up "How to build a PC part 3". My link didn't post.