In article <0E4253CA-4C5D-4B7E-9459-29C01030EAC6@microsoft.com>, Ali
wrote:
A product key is a series of numbers/letters that you receive when you
purchase Office. You enter it while installing Office or later (in the
case of free trial versions).
Be certain not to lose the product key or your CD. Without both of
them, you won't be able to install or reinstall Office.
If you purchased Office online, be sure to make a backup of the
downloaded file (to CD or other safe media) and to save the product key
someplace safe as well.