Dynamic CRM 2015 trial installation / Activation

Hi,

I have download the Dynamic CRM Server 2015 and install from below link. but it dint ask any key and it work for month I guess but not its now working but when I apply the below key its showing error message like below. 

Download CRM 2015 setup from below link 

http://www.microsoft.com/en-us/download/details.aspx?id=45012

Installed version 7.0.0.3543 

Key try to apply 

• Microsoft Dynamics CRM Workgroup Server 2015 (5 CAL limit): XY8GN-DF2MC-FV482-YM9YP-HH6H2

Regards,

-Dhaval M.