cannot use key for Microsoft Office

Question

I tried entering my microsoft office key on my old computer and it wouldn't allow me saying my windows 7 version is too old so i went and purchased a new computer with windows 10 and now I'm being told my key has already been used

Answer 1

Hi,

Something here might help:

This product key has already been used
If you see this message, it's because your product key has already been redeemed on this site. To install Office or manage your account, go to Microsoft account, Services & subscriptions page and sign in using the account that you used to buy or subscribe to Office.

If you're trying to share your subscription, see Share your Office 365 Home subscription.

Reference:
Get help with product key errors on Office.com/setup

Best regards,
Leon

Answer 2

As Leon replied, in case the key has been redeemed on Office.com/setup and Microsoft365.com/setup, you would get this error when redeeming Office again.

Please make sure the Microsoft account that you bound with Office is not lost. Then sign in to your Services & subscriptions page, then install the Office.

Besides, if you want to check the usage of this key, you may contact Microsoft to have a confirmation via phone or online chat.