Yes there is a tool (Offline & Online) for Windows 7 which can tell if your PC is genuine.
You can just download the old tool from the link
http://go.microsoft.com/fwlink/?linkid=52012 and run the tool to check your copy of Windows 7.
Alternatively if you want to do online validation, just move to
http://www.microsoft.com/genuine/validate/ValidateNow.aspx?displaylang=en and click on
validate windows to validate your copy of Windows.
The tool which you download to your PC from the link
http://go.microsoft.com/fwlink/?linkid=52012 is actually a validation tool for Windows XP but it can also run on Windows 7 including Windows Vista.
Since Windows 7 and Windows Vista have Windows Activation Technologies instead of Windows Genuine Advantage notifications so wga tool earlier working for Windows XP is actually not meant for Windows Vista or Windows 7.
Windows 7 and Windows Vista have inbullt tool and services collectively called as "WAT (Windows Activation Technologies)" and is installed when windows is installed. Later on Microsoft releases updates to WAT to check activation and licencing hacks.
But the main problem here is that Microsoft Download center uses the earlier version for validation but that you can also download and install on your PC if you download any WGA protected download from the download center like from
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=26f11f0c-0d18-4306-abcf-d4f18c8f5df9I hope that this answer would satisfy your query.
Regards,
Ravi
