After installing SharePoint 2010 successfully on Windows Server 2008 SP2,   

I tried to create a Team Site, but it gives me the following error:   
**"The trial period for this product has expired"**

i tried to google it, but with no luck!  

can anyone help please ?  

note that i have installed SharePoint as a **Single Server with built-in database** on a Windows Server 2008 SP2 (not activated yet but it's trail period still valid for 59 days)