Reboot and try tapping the F8 key to see if the Repair Console is located on Advanced Boot tools. If so you can try running the steps given without the CD although the CD will work better.
Burn a repair CD so you have more options: System Repair Disc - Create
From the F8 or CD Repair console, open a Command Line to make sure Windows 7 partition is still marked Active: Partition - Mark as Active
Then run Startup Repair repeatedly. If no installation is found to repair, try running from Command line: bootrec /fixmbr followed by bootrec /fixboot to see if one shows up so you can run Repair on it.
If not, browse in to see if you can find any files to copy out: Copy & Paste - in Windows Recovery Console
Your options are then to order factory Recovery Disks from Tech Support or locate any Windows 7 retail installer to unlock all versions to reinstall the licensed version with the Product Key on COA sticker: Windows 7 Universal Installation Disc - Create