A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
This fixed it for me.
From http://office.microsoft.com/en-gb/excel-help/repair-office-programs-HA010357402.aspx
Windows 8
- Press the Windows logo key + X to see a list of commands and options. (Basically a quick way to get to Programs and Features in Control Panel.)
- Click Programs and Features.
- Click the Office program you want to repair, and then click Change.
- Do one of the following:
- In Office 2010, click Repair > Continue.
- In Office 2013, click either Quick Repair or Online Repair.