Attaching a debugger to the BootCamp control panel, one can see that the settings are written with an
IOCTL of the format
CTL_CODE(FILE_DEVICE_MOUSE, 0x801, METHOD_BUFFERED, FILE_ANY_ACCESS). The data written matches what is found in the Windows Registry at
HKEY_CURRENT_USER\Software\Apple Inc.\Trackpad\Mode. I've determined the format of this entry to be:
0 1 1 0 1 1 1 1 0x6F
| | | | | | | |
| | | | | | | tap to click
| | | | | | dragging
| | | | | drag lock
| | | | [reserved, always 1]
| | | [reserved, always 0]
| | secondary tap
| secondary click
bottom left (0 for bottom right)
I wrote a quick program that will read this registry entry and write the settings to the
\\.\AppleWirelessTrackpad device. Download it here (source code available, contributions welcome). Someone with Windows programming experience could add a nice UI and have it run as a service to detect and initialize when the device is [re]connected.
For my personal setup I manually changed the registry setting (0x6b: defaults, minus drag lock!) and run this program as a Windows Scheduled Task (at login). On the rare occasion that the pad loses sync between reboots, I just run the program again manually to refresh the settings.
Here is a sample registry file, save as plain text then double-click to apply:
Windows Registry Editor Version 5.00
Additional sample registry files available on the downloads page.