Most SSD's are 2.5" which are the same size as a laptop HDD. Regardless of which version of SATA you have an SSD should work. It just may not be as fast as it could be. Which is still much faster than a spinning HDD. As for your OS, you should be able to install Win7 to it and just use the license key that is on your laptop for activation. You will need a Win7 install disk.