Have you installed libusb-win32? I think libusb-win32 has this bug and I am facing the same problem as you in the computers with libusb-win32 installed. However I am not the administrator of the computer and I am not so sure whether this is exactly the reason. I guess that LIBUSB-WIN32 disabled the Windows notification of USB device unplug/plug. When you reset the PICDEM, the PIC FS USB is unplugged and then plugged. Are you the administrator of the computer? Regards, Xiaofan -----Original Message----- From: Pierre B Sent: Thursday, August 04, 2005 3:05 PM Hello, I imagine well the driver can not be signed by Microsoft. But it changes nothing : it doesn't want to be installed. Thus my problem must be elsewhere. Can it come from the program? Because I've noted that each time I started again the PC the device functioned correctly ... until I resetted the PICDEM board. regards, PiR -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist