Need help with windows keys n stuff

[KingBaby]

So I have a copy of windows that is OEM and I am going to buy a new key off software swap on reddit. Do I need to do A clean install or can I just change my key then transfer over my hard drive to my new build? And lots of build guides have reccomended software swap on reddit but is it legit? one of my firends says it is but I dont know him in real life so it is just a bit sketchy all in all.

 

Thanks for the help!

[Shimejii]

Its legit. I reccomend clean install every time, its easier and faster than trying to transfer, and you can always transfer files over later.

[KingBaby]

Its legit. I reccomend clean install every time, its easier and faster than trying to transfer, and you can always transfer files over later.

I have a portibal harddrive should I just move everything that I need (like files and pics etc) and format because I do have a dvd to start from scratch with.

[Shimejii]

If you want to sure  

[KingBaby]

Thanks, just needed to reasure myself