How to solve invalid product key Windows 7 activation error

Windows 7 is the error less OS in the history of Microsoft.Some times we get an error while activating Windows 7. The error may say that the key entered by you is invalid. This article explains how to solve this kind of problem.After installing Windows 7, we have to activate Windows 7 after certain time period. Many of you might have got this kind of error ( Activation error of invalid key). For activating Windows 7, you need to type the product key.
During the activation of Windows 7, some times you may receive an error 0xC004F061. The meaning of this error is that you are using a product key for an upgrade version of Windows 7 and there is no previous version of Windows on your computer when Windows 7 was installed. So in order to install the upgrade version of Windows 7, you must install Windows Vista or Windows XP before installing the Windows 7. You may also receive an error indicating that you have entered an invalid key. To solve these kind of problems, please try the following solutions:

Type correct license key: First of all make sure that you are typing the correct license key. You can check for the product key sticker on your computer or it may be inside the Windows 7 installation package.

Is the product key intended for the version of Windows 7 that you are trying to activate?: You should make sure that the product key that you are trying to use is intended for the version of Windows 7 that you are trying to activate. For example. a product key for Windows 7 Basic cannot activate a Windows Ultimate product.

Make sure that the product key is valid for a full install of Windows 7. If it is only for an upgrade version of Windows 7, then you should have previous versions of Windows installed in your computer.

If you do not have previous versions of Windows installed in your computer, then try to get a valid product key and installation DVD for a full install of Windows 7.

If the product key for an upgrade version of Windows 7, then you install either Windows Vista or Windows XP and then upgrade with Windows 7 for which the product key will work.
If you still continue to get the error message, then you can leave the license box empty and continue with installation to finish the set up of Windows 7. But you will have only 30 days period to activate Windows 7.