Moving Microsoft Office from one Mac to another

I recently bought a new MacBook to replace my iMac where used Microsoft Office for Mac. I set up my MacBook and transferred everything over, but couldn't run Office without the activation key.

I deleted and installed a trial of office 365, and used until the trial expired. Now I think I have the activation key (from looking it up—it's the same as the product ID?) I tried moving over from a backup, but I'm getting the Office 365 activation, and does't accept the code I have.

I have tried migration assistant and replacing the library files but nothing. I keep getting this screen now matter what I try:

Can I move the original Microsoft Office suite over from the iMac to my new MacBook any other way to stop getting this massage? I think I got as a download years ago, so no disc.

I am also using Microsoft Office 2008 on a new 5K iMac which is running Yosemite and I used Dropbox to get it onto the Mac –no key and no migration assistant.
It runs perfectly.
Microsoft tried to tell me that Yosemite was not compatible with office 2008 but that is not the case in my experience.