What you got is an OEM (Original Equipment Manufacturer) Disc. It is legit if it wasn't used for any activation yet. But if it was registered before thru Windows Activation, then it is considered as "pirated" or counterfeited. The issue is not on the disc, but the "key" for activation.

Don't just ask them to install for you. Ask them to ACTIVATE for you the legit key (if you are after legit copy)