Windows not genuine

Does it give you the option to verify it online?  If so give that a shot - if not, then there should be a phone number for you to call Microsoft.  Since it came with the computer, it should be a valid license.  
 
When did this message start happening?  Did any hardware get changed in the computer recently?

Hello and Welcome to the Webroot Community!
 
Try to Activate see here: http://windows.microsoft.com/en-us/windows/activate-windows#1TC=windows-7 and if need be try doing it on the phone. https://support.microsoft.com/en-us/kb/950929/
 
Windows 7To start the Product Activation Wizard, follow these steps:

1. Click Start[img]http://support.microsoft.com/library/images/support/kbgraphics/Public/EN-US/VistaStartButton.jpg[/img].
2. Right-click Computer.
3. Select Properties.
4. At the bottom of the window, click Activate Windows now.

In the Product Activation Wizard, follow these steps:

1. Click Use the automated phone system to activate. [img]http://support.microsoft.com/Library/Images/2779589.png[/img]
2. Click the drop-down menu, select the location that is nearest to you, and then click Next. [img]http://support.microsoft.com/Library/Images/2779591.png[/img]
3. The Product Activation Center telephone number is displayed under Step 1. [img]http://support.microsoft.com/Library/Images/2658932.png[/img]

Thanks,
 
Daniel 😉