Invalid Product Key? Get the Right Key
Another reason causes much frustration. You may have asked for a product key that does not match your version of Windows 7. An invalid product key is rare, but it surely is a good reason to have Windows 7 installation problems. In this case, you need to contact the Microsoft Support Center and get the correct activation key. You can get the activation code through email or telephone. You can also use Internet-automated activation. Activation through the Internet, also called online activation of Windows 7, requires minimum effort.
To get the activation key over the telephone, you need to know the version of Windows 7 as well as the serial key that you used to install the operating system. You can locate the serial number on a sticker on the box in which the installation CD was shipped. You can also check the version number on the box. If you downloaded the OS, you will have the version number and activation key in the welcome e-mail. Though telephone activation is also faster than emails, it often creates frustration as the MS call center keeps you on hold seemingly forever.
Another common reason for Windows 7 installation problems is using an upgrade key on a clean reinstall. This means that you boot through the DVD drive and format the entire drive to install Windows 7. In this case, the previous operating system is removed and you can install the OS successfully, but then you face a Windows 7 activation problem. Many users do not realize that it was meant to be an upgrade.
If the activation process terminated with an error code: 0xC004F061, it is definitely the problem where you are using an upgrade key on a clean install. In this case, go back and reinstall the Windows operating system you were using prior to installing Windows 7. After installing the previous OS, install Windows 7. Once done with the installation, enter the upgrade key to fix the problem. This error is most common among all the above described Windows 7 installation problems.