Invert scrolling on Windows Bootcamp
From user3669959's linked answer:


Open the Mouse settings in the Control Panel
Click on the Hardware tab, "HID-compliant device", Properties
Click on the Details tab
Choose Device Instance Path in the Property drop down menu
Note the VID value
Run regedit
Edit HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\HID\VID_???\VID_???\Device Parameters, where the ??? is the VID value we just found
Edit FlipFlopWheel
Change the value from 0 to 1
Close all programs
Reboot


This worked for me on a Windows 7 64 bit PC, using the Boot Camp 5.1.5769 AppleWirelessTrackpad64.exe driver.

References:

http://tsentas.net/windows-bootcamp-reverse-scrolling/