Reset the Microsoft Office Custom Dictionary
To reset the dictionary to the defaults for Microsoft Office applications:
1. Open a Microsoft Office application, such as Word, Excel or PowerPoint.
2. Click the Office Button or File menu (in the top left) and then click Options.
3. Click Proofing, then click Custom Dictionaries under “When correcting spelling in Microsoft Office programs”.
4. In Custom Dictionaries, select the CUSTOM.DIC and click Remove.
5. Click OK, then click OK again.
6. Close the Office program.