I just published a new 20140901 MegaDrumManager version. In this version I tried to address issues experienced by many (most?) Windows users with 'Firmware upgrade' procedure. As far as I can judge all these issues should now be resolved. I also implemented some internal improvements. I tested it on Windows 7 64bit and Windows 8.1 32bit. Anders (aka angr77) tested it on Windows 8.1 64bit. Get the latest MegaDrum Mager from  MegaDrum Manager Download page.