It's easily to check your Windows 7 licence information by the command prompt.
1.Pressing the Winkey+R Shortcuts to open a command prompt. Then type " cmd " and press enter.
2. In the command prompt type the following command, and A Windows Script Host will pop up informing you of an invalid combination of command parameters.
slmgr: display the basic information
slmgr /dli: display the current license information
slmgr /dlv : display detailed information on the current license
slmgr /xpr : display the expiration date for the current license
slmgr /rearm : rearm Windows and extend the grace period