Windows – Does the two-fingered secondary click not work in Windows8.1/Bootcamp

Go to Device Manager and uninstall (and delete drivers) for the two Trackpad devices then rescan for hardware. After which, then go find your Boot Camp drivers, and don't run the full setup, but instead find the folder that specifically has the driver install packages in them and install the ones that are along the lines of "Apple Multitouch Trackpad." After this, go to your Boot Camp options to make sure that it now sees your Trackpad. You should have full functionality restored after this.

Did get the answer from this forum post: How do I get my Macbook Pro trackpad working on Windows 8

Finally got this working, thanks to a person named "turbostar" over on discussions.apple.com:

1. Re-run Boot Camp Assistant to remove the Windows partition and restore the full Mac HD as a single partition.
2. Run a PRAM reset (restart, while screen is still black, hold down ⌘+Option+P+R and keep them pressed until you hear the startup sound a second time).
3. Open disk utility and repair permissions on the Macintosh HD partition. TWICE.
4. Start Boot Camp Assistant again.

Seems hokey. With those instructions I thought I would also have to stand on one foot, point to my nose, rub my belly, and hope for rain. But it did end up working.