On Thu, Jan 4, 2018 at 5:49 PM, David C Brown wrote: > I have tested the same set up on a desktop machine running Win7 and it > fails in exactly the same way. > I have also tested it with the shortest possible cable - less than 5cm - > and still get the failure so I doubt that cross-talk is the problem.d > The logical conclusion is that, whatever Microchip say, MPLAP8.92 is not > fully compatible with Win7. > For XP emulators the lord be thanked :-) I dont think it's a compatibility issue at all. Either something is wrong in your system (DLL corruption and or whatever), or there is still crosstalk, i must say. There's no logic in the compatibility issue. Another way to debug (painful way) comparing USB messages being sent in bot= h the situations. http://www.usblyzer.com/ Cheers, Manu --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .