I'm unable to install USBDK any way possible on WIN7 64bit. When I first proceeded to install from GIMX 4.2 installer , it failed that way that installer waited endlessly . I had to kill process each time. After this I had to force shut down of windows with power button. In mean time any USB device stopped working at all, even mouse. OK , I restored image with Clonezilla that luckily I made 3 days ago

Ok, after unplugging everything from computer, installing new Gimx and trying few times , finally it get to work. I don't know what really helped, for sure at least partially helped disconnecting from docking station which had attached esata drive powered form mini USB. These USBDK drivers is a huge interference to the system. At the end Gimx started to work when I updated libusbk dll to the latest version.