A family of Microsoft word processing software products for creating web, email, and print documents.
Since the problem appears to be with double-clicking the files to open them, try repairing Office from Control Panel. See https://support.office.com/en-us/Article/Repair-an-Office-application-7821d4b6-7c1d-4205-aa0e-a6b40c5bb88b?omkt=en-US.