Scanpst.exe may be the answer. Don't know if you are still having a problem; but wanted you, and others who may be to know the solution I had to similar indexing issues even after upgrading to Windows 8.1.
I had been having an issue for a couple of months prior to the upgrading -- it was just that it continued even after upgrading to 8.1. After repeated attempts at rebuilding the index, which would seem to stall at about 5000 to 8000, maybe 11000 files,
and attempting other solutions suggested in posts following on this issue (including registry changes), I began to get clues that the indexing was stalling in Outlook files,
I decided to try once again running the scanpst.exe on my Outlook files, notwithstanding that I had run it once before not long ago after cleaning out old emails. What I discovered was that a single pass with scanpst.exe does not necessarily do a complete
repair of the Outlook files. It may take two or more (actually took me three) before it returns a no error report. (In addition, I had a total of 4 outlook primary folders; and this time took the time to clean all of them, notwithstanding that I had taken
them out of the indexing process.)
Good news is that repairing the Outlook files solved the problems I had been having. In a few hours my index was rebuilt to about 120,000 files (a reduced target after deselecting several folders from the Windows index, while I was experiencing the problem).
After that success I added back folders that I had excluded from indexing, and within another 24 hours or so I had a complete index of my 336000 or so files that I want to have in the index. [Actually right now, the indexing options box reads "Index complete"
at 347,696 items indexed.]
P.S. Since getting the indexing fixed I installed the trial version of Office 365, which is terrific as well, so I now have the system that I have been dreaming of -- having started using computers in the mid-80s, having 8.1 and 365 is like living in a
new world.
Hope this provides a solution for others, as if you are having a Windows indexing problem, I surely know how frustrating it is -- particularly when you depend on it to find your work.