Windows OS Options for new build

[Strollerdad]

My budget friendly HP Desktop bundle from a couple of years ago was great for school work when my Macs crashed but now I want to use it for video editing and it just isn't powerful enough (AMD E300, and 4gb of ram at 1066). As a result I am going to be jumping into my first computer build here pretty soon.

 

The part that confuses me is the OS issue. I'm running windows 7 on the desktop and 8.1 on my laptop and honestly I like 8.1 better but I'd love to upgrade to 10 when it comes out. Since it looks like both OS's will be able to upgrade free that will work out great except that I won't be keeping my all of my desktop. 

 

Here's my questions:

 

Can I transfer windows 7 to the new machine even though it's an OEM license or do I wait for the Windows 10 upgrade and then transfer it to the new machine?(assuming that's possible, and who knows when that will even come out) Or would it just be best to purchase 8.1 and upgrade from there?

 

Sorry for the newb questions, my own searches haven't really produced a clear result.

 

Thanks in advance.

[Equilibrium_FOOL]

You can use the windows license on the new computer, as long as the other is deactivated. 

[SubTract]

If its an OEM license the key is tied to the motherboard so it will not let you use it on another computer. You could try calling MS and telling them you've changed HW but it is unlikely they will help you.