Originally Posted by Stefan Blom

Click the Office button, and then click Word Options. In the Proofing category, click AutoCorrect Options. On the AutoCorrect tab, make sure that "Replace text as you type" is selected. If you don't see "(c)" listed, with the copyright sign as the replacement, you can recreate it. (In the "Replace" box, type in (c) and then press Alt+0169 to insert the copyright sign in the "With" box. When you are done, click Add, and then OK.)