I boot up to Windows 7, clicked on START, and right click on Computer and chose "Manage", and then I right clicked on a primary partition which wasn't the partition for C: but just a useless partition instead. (I repeat: it is NOT the partition for C:. It was G:).
After I right clicked on that useless partition, I chose "Delete" and confirmed I want to delete.
Then after 30 seconds, Windows 7 blue screen, and I cannot boot up Windows 7 any more. The suggestion on screen is that I boot up Windows 7 from the DVD-ROM, chose Repair, but it didn't repair it. The repair tool showed the Windows 7 partition is 0 MB. If I boot up to Vista instead, and chose Disk Manager, it showed the Windows 7 partition now as "Free Space".
How can I get back Windows 7 (with all the data)?