If the Windows 7 activation isn't done within the assigned time , a lot features of the operating system are disabled.If you haven't activated Windows 7 during the installing procedure, you can activate it manually as well. Then You could meet some problems when activating Windows 7 on your personal computer .

There are 4 usual problems related with Windows 7 activation:

1. Invalid product key when activating Windows 7

The error "Invalid Product key" may happen if you have typed the wrong product key, or the product key does not match the Windows 7 version.There are 6 versions of Windows 7 :Windows 7 Starter,Windows 7 Home Basic,Windows 7 Home Premium,Windows 7 Professional,Windows 7 Enterprise and Windows 7 Ultimate.You should check your product key matching your Windows version.

2.Error message "Your activation period has expired"

The error may be caused by that the activation period of Windows 7 has expired. Every operating system comes with a time frame by which it has to be activated failing which it can't be loaded on a  computer. So is the case with Windows 7. You need to look for professional service to fix this problem.

3.Windows 7 activation error: "0xC004F061"

This error happens if you are using the product key for an upgraded Windows 7 and its previous version hasn't been installed on your computer. If you want to install the upgraded Windows, you must have previous Windows 7 installed on your computer.

4.Error message "Product key in use on another computer"

This problem occurs if you are attempting to activate the Windows 7 on more computers using one product. Windows 7 can't be activated on more computers than the number assigned in the Microsoft Software License Terms. You must check the number of the Windows 7 operating system should be activated.

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