I want to get a new pc, but i dont want to buy another windows 8.1. how can i easily copy only my os(windows 8.1) to another ssd, then put that ssd into a new computer?
If you have retail Windows then use the installation disk.
I have an OEM version, and I don't think I will be able to use the same product key on 2 different computers
If you purchased the license then you can use that key again as long as you remove it from the old machine beforehand. So as long as you either transfer the drive into the new machine or wipe the drive you would be fine.
Did you buy your copy of Windows 8.1 or did it come with the system? OEM licenses that come with (HP, Dell, etc or even OEM licenses from hobby stores) do not permit you to transfer the license from one system to another unless you are the system builder (Kinda weird but that is the terms Microsoft set).
If you have retail Windows then use the installation disk.
I have an OEM version, and I don't think I will be able to use the same product key on 2 different computers
If you purchased the license then you can use that key again as long as you remove it from the old machine beforehand. So as long as you either transfer the drive into the new machine or wipe the drive you would be fine.