Stefan_Janosevic :
Well i want it to be just like it was when i bough it.
And i have a type of a virus that needs to be uninstalled by formatting.
Then you
do need to wipe the OS (and everything else) and reinstall.
Assuming you have a valid license key, you can download the official Windows 7 ISO here:
http://www.w7forums.com/threads/official-windows-7-sp1-iso-image-downloads.12325/
Drivers can be obtained from the manufacturers websites. (Do this before you wipe the drive)