How to install windows 7 from "Hard disk"

1. First of all u should have all the files of windows 7 for installation including the set up file .store all file in your hard drive and just remember that location
2. then restart your computer goto booting ,chose Hard drive
3. then go to the location where u store all files of windows 7 including set up file
4. then double click on set up file 
5. then the installation of windows 7 starts as in case of installation from a cd.
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