Windows on Mac with Boot Camp - which version/license key?

[ben_h100]

I'm looking to install Windows on my MacBook so that I can run some applications such as Packet Tracer/GNS3 for some Cisco courses that I am doing. Looking on amazon, it appears that there are multiple versions (Windows 7, 10, etc.). Prices vary significantly - will something such as this https://www.amazon.co.uk/gp/product/B01I7DOZX4/ref... be suitable? Is it legit?

Packet Tracer works in OSX to a degree, however I have been sent some official Cisco exe programs that so far, I have been unable to get to work at all.

[Simon.]

I don't 'believe' it's legal, after all Microsoft sell Windows 10 Home for £119.99 via the Windows Store.