Boot Hill Heroes has an interesting local co-op feature, however it’s difficult to acquire the right input devices. Because
it was developed in XNA, it only supports a keyboard and Microsoft Xbox 360 Controllers (wired or with a wireless
receiver for PC support) – which are not easy to come by.

Fortunately, there is some third party software that enables you to use a PlayStation 3 controller as a Microsoft
controller so it will work with Boot Hill Heroes. It’s a little tricky to set up, but it works.
You can use the USB wire that comes with a PS3 controller and plug it into a USB port on your PC. Then use this
software to emulate it as an Xbox 360 controller.
http://www.motioninjoy.com/download

Alternative
There is also an alternative software that does not need to activate a driver. This thread speaks highly of it, but I have
not tried it myself.
http://gtm.steamproxy.vip/groups/bigpicture/discussions/1/864976115177997027/

If you’re having trouble getting this to work under Windows 7, you probably need to install the Xbox 360 controller
drives too. You can do this at the following link:
http://www.microsoft.com/hardware/en-us/d/xbox-360-controller-for-windows