go into your Control panel, and go to the USB part of the device manager, on ALL USB devices (with your PK plugged in), turn OFF, the "Power Saving" and sleep mode stuff, so that the USB is NEVER goes into sleep mode, or hibernate.
PS, basically just like you do for the Smooth Stepper, if you need step by step, read the Smooth Stepper how to doc, that Jeff Brit wrote, it is on this site, or his site, but he goes through step by step how to STOP Win-blows from screwing with your USB roots and nodes.
scott