You might have mistyped your genuine product key.If you receive an error indicating that your Windows 7 product key is not valid when installing, it could be for the following reasons: In other words, if it came with Windows 7 Home Premium, you can’t install Windows 7 Professional. Start your computer using the Windows 7 installation disc or a USB flash drive, click Custom (advanced), and then click Drive options (advanced).īe sure to use the same version and edition of Windows the computer came with. You can do this to install Windows 7 upgraded version. But if you want a clean installation of Windows on a PC, you need to format the hard drive and reinstall the windows using its product key. It is recommended to install/upgrade Windows 7 while your current version of Windows running. If you bought a PC with Windows pre-installed, the original key comes pasted on the product by the PC manufacturer. If you purchase it online, the vendor will send your Windows 7 product key in the confirmation email you receive after purchasing or in the box Windows came in. This product key verifies that Windows has been used on given numbers of PCs that the Microsoft Software License Terms allow. Windows license key is a 25-character code. You get a Windows 7 product key when you purchase Windows operating system for one or more PCs.

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