To find a working product activation key for Microsoft Office 2003, users should search their purchased software's original packaging. Users who have lost their original product activation keys can either download a program to locate the keys in Microsoft's Windows Registry or purchase new copies of Microsoft Office software.
To locate a lost product activation key, users can download and install a key-finding program such as Keyfinder Thing. Once installed, this program searches the Windows Registry to find, decrypt and display the user's unique product activation key. Alternatively, users may purchase new copies of Microsoft Office, which come with new unique product activation keys. However, as of 2015, Microsoft no longer sells nor supports Office 2003, so the software may be difficult to find.