Windows 7: Windows 7 activation expired

My laptop says that the windows activation period expired and asks me for a activation code. Well, i did a little research and found a way to see how many days remaining left for the activation. When i saw it in the control panel, it says that my windows is activated and even shows the activation key! My desktop is still black and it still prompts me that it is still not active. What should i do? Please help me.

Welcome
The best thing to do is activate by phone
Activate Windows 7 by Phone
If there are any problems during this process an rep will come on the line; explain to him/her and you will be activated.

Activation Expired messages are usually caused by Beta software -
To properly analyse and solve problems with Activation and Validation, we need to see a full copy of the report produced by the MGADiag tool
(download and save to desktop - http://go.microsoft.com/fwlink/?linkid=52012 )
Once saved, run the tool.
Click on the Continue button, which will produce the report.
To copy the report to your response, click on the Copy button in the tool (ignore any error messages at this point), and then paste (using either r-click/Paste, or Ctrl+V ) into your response.
- **in your own thread**, please
Please also state the Version and Edition of Windows quoted on your COA sticker (if you have one) on the case of your machine (or inside the battery compartment), but do NOT quote the Key on the sticker!
How to Tell