Quote: Originally Posted by mrperu
My friend upgraded my windows 7 home premium x 64 illegaly to a cracked version of windows 7 ultimate. I want to restore it back to home premium but it came preinstalled on my laptop so i dont have a product key to enter to re validate my windows. Please help!
There is no way to downgrade. You will need to do an install from your Windows Home Premium OEM media. They usually send these discs as "Repair Discs". Using such OEM media, you should not need to input any product key since Windows will look at your BIOS/EFI for the product key.
About an OEM Windows install media, even being the same version as what came with your computer, if is not an OEM, or if is an OEM from a different vendor as yours, it may ask for a valid product key. Get a media from your manufacturer and it should be activated automatically. There are other "ways" to fix that besides reinstall, but I believe this may be incorrectly tagged as "piracy" (tip: "slmgr.vbs -ilc your-manufacturer.xrm-ms") - although this is an official tool from Microsoft, it usually ends up being "misused".
Previous advices are also true: product keys are always labeled on each and every computer from any serious manufacturer. You should only use an OEM install media. Again, BIOS activation or OEM product keys will not work with a retail copy of Windows.