Trackpad tab not in Boot Camp control panel

What worked:

1. Re-install Windows (from within OS X, remove the boot camp partition, use boot camp to download the windows support software to a USB drive, then make new partition).

2. The windows support software had the correct drivers but not the full setup.exe. So also download Boot Camp Support Software 5.1.5621 to your USB drive. Replace the folder inside BootCamp5.1.5621 called "$WinPEDriver$" with the one (same name) Boot Camp downloaded in step 1.

3. Install windows. (if it restarts to complete the install and starts the install process over again, watch the install progress and unplug the USB drive when it restarts)

4. Open the BootCamp5.1.5621 folder > BootCamp > run setup.exe. Without following step 2 you get an error that "This version of boot camp is not intended for this computer." If you just force it using CMD and not step 2, then you run into the problem of this original post (no trackpad options, no right click available).

5. Click on the BootCamp icon (gray diamond) in the lower right tray, click on BootCamp control panel, (click Yes allow if it asks you), Trackpad tab, and make sure the two fingers secondary tap is checked and/or secondary click is checked.

6. Voila! Hopefully this helps someone else!!

Thanks all for your suggestions!

Thanks for the suggestion. But the Boot Camp Windows support software I installed is what is suggested for my MacBook Air Mid-2012. (The link you provided talks about the windows support software, is there a way to update Boot Camp software itself?)

Thanks, @LonerT, but the Boot Camp support software version 5.1.5621 is what is suggested for my specific model. :/