How to boot\format windows 7

1.Open your computers bios 
2.keep cd-rom in first priority and save it
3. after the in the screen "press any keep to boot Will appear" press any key you want
4.after that it load its file
5.press install
6.choose if you want to upgrade or  custom to format
7.click in drive option and format which drive you want format
6.after that setup will start and follow the instruction..