Im taking apart an old build and reusing an SSD from it. The SSD has the old operating system on it. Can i throw the SSD in any external enclosure, plug in via usb and format it? And if i can how do i reformat this using win 7 just quick format the drive?
You don't even need the external enclosure; the Win7 installation procedure will reformat for you if you select that option.
However: I strongly recommend clearing the entire SSD with Secure Erase before doing your install, so that it will know that all of the blocks are unused. You can download the boot CD for Parted Magic, which contains Secure Erase in the erase drive tool.