Available for multiple PCs under full retail pricing.
No device can run two copies of the same Windows version at once.
Yes, we have two license keys available.
No, just one option was provided, that's why you're concerned.
It wouldn't work to reuse the same license key across multiple devices. If you need further assistance, let me know.
Varies by edition. Typically, one key equals one computer. Free keys from a college DreamSpark account usually cover two installations.