Some programs install “Trusted” certificates on your computer that work inside Office applications, etc, that are malicious, and cannot be removed from within the program itself.
To delete unwanted Fraudulent or Unwanted Certificates:
- Hit Start, and click in the search box
- Type “certmgr.msc” and hit Enter
- Browse to the category you want, like “trusted”, “untrusted” etc
- Open Folder and Delete desired Certificates