|Sometimes a repair facility will restore Windows using the wrong disk. Windows 7 has a feature to change the key while in Windows. |
I suggest you try booting into Windows Safe Mode or last known good configuration.
If you can get to Windows then go to Manage> storage> Disk Management. Post all information listed for the C: partition.
If that doesn't work then I suggest you use a live version of Linux to access the computer. Live versions to not require installation. They run directly off the media they are on.
Linux Puppy is compact, Windows feel to it and is free. You can install to CDR or flash drive. Get the flash drive version from the link below. You should be able to copy any files to CDR or DVDR or to an external hard drive or second internal hard drive.