I have committed a couple of Windows to the public RFIDler github.
Firstly RFIDler Installer - a GUI tool to help install the RFIDler device driver.
There are 2 binaries, for x86 & x64 versions of Windows.
RFIDler Monitor - lists all connected RFIDlers, their COM ports or if they are in Bootloader mode.
Some options help monitoring other Microchip development boards presenting as serial ports, other serial port, and similar devices remembered by Windows but not currently connected.
They both work pretty reliably on Windows 7 for me, and should work in Windows XP & later. (No Itanium or Windows RT version planned.)
I hope these are useful. Feedback welcome. :-)