Here, is a separate set of Windows 8 product key which you can use –
For re-installing Windows 8 developers preview, use the following key :
For re-installing Windows server 8 developers preview, use the following key :
Also, Read our post on Windows 8 Infographic.
Thus, when Windows 8 is reinstalled you can see the following screen, asking for the product key.
You can go ahead and copy and paste the key provided in the beginning of this post. These keys are provided by Microsoft, and they are also available on the MSDN forum. Alternatively, you can click the skip button if you don’t want to insert the key.