Re-installing but switching from MBR to GPT

[youlikesalad]

I finally got a working copy of Windows 8.1 retail 64-bit, but made the mistake of installing it on an old machine that only supports BIOS/MBR. What I'd like to do is take the hard drive out, stick it into a newer machine, wipe it clean, convert it to GPT, then re-install Windows via UEFI. Can I just re-enter the same product key, or do I have to call Microsoft for this one?

 

[USAFRet]

I finally got a working copy of Windows 8.1 retail 64-bit, but made the mistake of installing it on an old machine that only supports BIOS/MBR. What I'd like to do is take the hard drive out, stick it into a newer machine, wipe it clean, convert it to GPT, then re-install Windows via UEFI. Can I just re-enter the same product key, or do I have to call Microsoft for this one?

In a whole different system/motherboard, you may have to call MS if it does not activate.