These forums have helped thousands of users clean reinstall factory OEM with a clean copy of the OS they bought and own. This is something which almost all tech enthusiasts do, to get the most pristine installation possible without the factory bloat or useless utilities which have better versions built into Windows 7.
What we don't do is help with bootleg or pirated copies. A Product Key on COA sticker is required. How they get the installer is up to them as we cannot post download links here as it is thought to encourage piracy.
Just a few years ago most OEM's provided a clean-copy Installation DVD as well as the Recovery disks larded with bloatware. Under pressure from bloatware sponsors they gradually stopped providing the DVD's to try to enforce factory bloatware upon users who own the hardware and OS and should be able to use it any way they want.
Here are tips for getting a perfect clean reinstall of factory OEM: Reinstalling Windows 7