1. Go to Start and type in programs
  2. Then select Add or remove programs
  3. Then click on View installed updates

  4. To make it easier to locate the patch to remove make sure to sort descending by clicking the Name header and making sure all the Group by is off.

  5. Locate Security Update for Microsoft Excel 2010 (KB3178690) 32-Bit Edition and right click on it and select Uninstall

  6. Press Uninstall
  7. Reboot computer