On Thu, May 26, 2011 at 1:28 AM, David Novak wrote: > I remember when switching computers a while back, the ICD2 automatically > download new firmware. Does the ICD2 need different firmware depending > on if it's operating from Windows XP or Win7 64? If so, how do I force > that download? No you do not need different firmware for XP or Win7 x64. Since it works under Win7 x64, it is of new version of ICD 2 using the PIC18F4550 as the USB MCU inside ICD 2. The difference will be the computer side. ICD 2 is not that reliable and I guess certain grounding issues can cause the problem you described. Maybe you want to try a different USB port or get a USB hub in between to see if that helps. --=20 Xiaofan --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .