This was brought from Amazon and not from Amazon marketplace sellers. It is the original Microsoft OEM version of Windows 7 Pro 64-bit. Inside the pack there is a Microsoft Windows 7 Pro 64-bit install disc and the COA (Certificate Of Authenticity) Label.
I used it to upgraded my old Vista desktop computer by installing it on a new SSD so I didn't have to worry about copying/backing up data from the old hard drive as it became the secondary drive.
It was a simple procedure to open up my computer and plug in my new drive. I entered BIOS settings and set boot up from optical drive and activated the AHCI setting (only if you're install a ssd). Then save and exit the BIOS settings and waited for my computer to start up (make sure you have the install disc in your optical drive).
The on screen instructions were simple to follow and I entered the serial number when asked (see COA Label). After disc installation, I used windows update, there were over 180 critical/important fixes. The whole thing took about an hour.
I find Windows 7 to be way better than Vista (and Win 8.1) so it was a worthwhile upgrade and my computer should have a few more years of useful life.