to install plug in:
first, follow readme in "hb04 usb driver" folder to install driver

place both "XHC-HB04_driver_plugin.m4pw" and "XHC-HB04_driver_plugin.sig"
in your Mach4 plugins directory (default install location is "C:\Mach4Hobby\plugins" )
start Mach4 

if the following error message appears:
"failed to laod shared library 'XHC-HB04_DRIVER_PLUGIN.M4PW' (error 0: the operation completed successfully.)"
you will need to install Visual C++ runtime libraries (i'm working how to eliminate this step)
navigate to: https://www.microsoft.com/en-us/download/details.aspx?id=53840
select vc_redist.x86.exe and install

if the plugin does not appear under "configure->plugins" goto "configure->mach" select the "plugins" tab and enable the "XHC-HB04 MPG" plugin

restart Mach4 and it should work!