Windows 7: Install Windows on a New Computer Using same key

Hello everyone I think I know the answer to this but just asking to make sure. So I was going to sale my Custom PC that I got Windows 7 a year go on it. I was wanting to know if I sale my computer without installing windows or anything on it if I then can turn around and install it on my iMac using the same key.

This should clarify it for you.

Differences Between Retail, OEM, System Builder, Volume Licensing, Full or Upgrade License for Windows « My Digital Life

If you sell it with windows activated on that pc, then no, you can`t reuse your key as it is already in use. I would wipe the hard drive and keep it.

Are you saying you never installed windows on it ?

Is Windows 7 installed upon the PC now? If so Go to Control Panel>System page, scroll down to Activation information and look at the Product ID. Does it have "OEM" in the string? If so it is locked to that computer for life.

If there is no OEM in the Product ID string then it is retail and can most likely migrate to another PC. To find out for sure ask your computer builder or call MS Customer Service.

He says it`s a custom pc, and goes on to say he never installed windows so I have no idea what he`s saying.