slwelch: thanks for the info on the KB.
I finally got fed up with the daily chkdsks on Win10TP and decided to reinstall from scratch. I "cleaned" the SSD and installed from the USB stick, this time, 64-bit, not 32-bit.
Since I installed clean, I had no apps other than the default ones, so I rebooted and started to install stuff. Around the third reboot, the CHKDSKs started again. Plus, the installations seemed to go badly. And, eventually, Win10TP would not boot anymore.
I booted into Win8.1 and ran CHKDSK on the Win10TP drive from there. Rebooted OK into Win10.
But shortly thereafter, the filesystem failures started again.
Suspecting that the SSD had actually gone "bad", I grabbed a hard drive and repeated the process.
First thing I noticed is that when I first rebooted after the installation, I saw both monitors, whereas on the SSD installation, I say only one!
However, after the second reboot into installing apps, the CHKDSKs started again, and within a couple more reboots, Win10 wouldn't boot again.
Tried this on a third drive this morning -- same process!
I simply don't accept that an SSD and two different hard drives, ALL of which have been working without problems for months on other OSs, have suddenly gone "bad".
This is build 9879 -- and it definitely appears to be "trashing" my drives.
I don't know why this is not happening to everyone, but I do know now, that I can not keep a 9879 install working without filesystem corruption for very long.
I'm running a surface test on the last drive, and when it finishes, I'll repair the filesystem (again) and try to do some Windows updates and see if that KB gets applied. Maybe that will fix the problems -- we'll see.
UPDATE: Surface test finished and found no problems on the drive.
UPDATE 2: Did a bunch of WUs and found KB3021937 was in the list. So, I will be monitoring the filesystem to see if this halts the daily CHKDSK problem.
UPDATE 3: Have been using this for a while now and am STILL getting CHKDSKs every time I reboot into Win8.1. SO, whatever this was supposed to fix (if anything) in the filesystem, it did not.