I had the same issue, the following solved it for me:

I first of all reinstalled [Cortana] as explained in a previous post. This did not solve the issue, I just want to include it for completeness (maybe not doing so makes a difference ;)

Then I opend up the indexing options and removed the user folder and the start menu folder (which can be found under C:\ProgramData\Microsoft\Windows\Start Menu). To do so, hidden files must be displayed. I clicked ok and closed the indexing options.

Then I reopend the indexing options, added the two folders again, clicked on advanced and enabled "Index encrypted files" and I clicked on Rebuild.

This solved the issue for me, now Word, Excel and all programs can be found with the search. Maybe not all of my steps are necessary.

I had the same issue, the following solved it for me:

I first of all reinstalled Cortana as explained in a previous post. This did not solve the issue, and I just want to include it for completeness (maybe not doing so makes a difference ;)

Then I opened up the indexing options and removed the user folder and the start menu folder (which can be found under C:\ProgramData\Microsoft\Windows\Start Menu). To do so, hidden files must be displayed. I clicked OK and closed the indexing options.

Then I reopend the indexing options, added the two folders again, clicked on advanced and enabled "Index encrypted files" and I clicked on Rebuild.

This solved the issue for me. Now Word, Excel and all programs can be found with the search. Maybe not all of my steps are necessary.