I'm on my phone, sorry for typos. You need to call Microsoft. This is from ganandorf's link for windows 8 and 7 (not sure which you have):
Windows 8:
At the Start screen, swipe in from the right side, or hover your mouse in the upper-right corner of the screen to display the charms menu.
-Tap or click the Settings charm.
-Tap or click Change PC Settings.
-Tap or click Activate Windows.
If your computer is not activated, PC Settings provides instructions that are customized to your activation error. If telephone support can provide help resolve your error, tap or click the appropriate link, that may resemble one of the following:
-Activate
-Activate by phone
-Contact customer support for help
Windows 7:
-Click Start.
-Right-click Computer.
-Select Properties.
-At the bottom of the window, click Activate Windows now.
-In the Product Activation Wizard, follow these steps:
-Click Use the automated phone system to activate.
-Click the drop-down menu, select the location that is nearest to you, and then click Next.
-The Product Activation Center telephone number is displayed under Step 1.
Let us know how it goes. Just get someone on the phone and they will help you.