Everything you ever wanted to know about your computer but were afraid to ask.
Windows 7 allow end-user to install the operating system without entering a product key during installation.
By not keying in a product key, users get to enjoy 30 days of free usage (rearm to extend to 120 days) without activating the operating system, as initial grace or OOB grace period.
Although end-user does not enter any product key into the system, Windows 7 uses a default product key to install the operating system.
In other words, Windows 7 has a default product key comes together with it that is the same for all installations of Windows, differentiate only by editions of Windows.
Although the default product key cannot be used to activate Windows, it can be used as a mean to create a Windows 7 unattended setup which automates the deployment of Windows without user input or intervention.
The default product key can also used when user decides to deactivate Windows and go back to trial period, where a product key is required, and the default product key will make it runs for 30 days without activation.
Here’s the list of Windows 7 default product keys: