File Block Settings
If you have certain file block settings enabled, you will not be able to open or edit older MS Office files. Checking these settings and changing them if necessary could resolve your issues.
Repair a Damaged File
If a file is corrupted, you might not be able to open it in Excel or Word. Using the Open and Repair tool could resolve this issue.
Reset File Associations
If someone changed the default file association for Word or Excel files, the program might not open as expected when you try to open a file. Resetting these file associations can be a simple fix. The settings required to make these changes are in Windows.
Repair MS Office
In some cases, the reason Word or Excel won’t open is because of a problem with the program itself. Repairing the program could be the best resolution.