Lego Mindstorms RCX RIS 2.0 IR tower Windows 10 64-bit driver
As many of the RIS 2.0 questions here suggest, you may be better off finding a different way of talking to that pedigree of brick.  

Virtual machines and other operating systems running other software are your best choices at this time. Running old, unsigned 32-bit drivers on Windows 10 presents a nearly impossible set of hurdles just to push a few bytes to a brick. 

I maintain a fork of NQC, for example, and I'm pretty sure I'll never try to get the USB tower part of that updated for Windows 64-bit. 

Another option is to find a classic serial tower and use a USB to serial dongle. I've had some success on that on OS X and earlier Windows releases.