Need help with the re-use of a windows key

[JML987]

So I'm upgrading my motherboard, and re-installing windows. When I make the change, and boot it up, it will ask me to insert the windows 8 CD and enter the 25 digit key?

I noticed on the windows 8 CD case it says "windows 8 ENG INTL for OEM software". I'm aware that OEM means I wouldn't be able to re-use the key again, as it's usually on pre-built PC's?
But this isn't a pre built PC, and I bought this CD from a vendor. My question is would I be able to re-use it again? I'm just confused as to why it says OEM on there?

 

[USAFRet]

Windows 8, you can reinstall as much as needed, even with a new motherboard.
As always, only one PC at a time.

 

[JML987]

Windows 8, you can reinstall as much as needed, even with a new motherboard.
As always, only one PC at a time.

Yeah I knew that, but the CD case said OEM on it, was just worried

 

[USAFRet]

Windows 8, you can reinstall as much as needed, even with a new motherboard.
As always, only one PC at a time.

Yeah I knew that, but the CD case said OEM on it, was just worried

For Win 8, the main difference is who you can call for support.
Retail, you can call MS.
OEM, you get to call whoever installed it. You. Or ask us...