It will be in a Windows.old folder and is not bootable. You will be booting to the new one installed.
When you power on the system, and go past the BIOS screens, do you get an option to choose an operating system - both of which are Windows 7?
Edit or use Tingle's method but do not change anything else.
OK you did not fully erase your drive before installing Win 7 again. This might give you performance issues on your SSD but more enlightened people here can help you.
Use Tingles method to remove the incorrect OS (this simply changes the boot.ini file I mentioned).
To further save space on your drive at least turn of hibernation as this will save HD space equivalent to your memory installed.