Graeme, Apologies for not including the complete log. Here it is. Hope it helps you tell me what's wrong. C:\Users\hewitt>spotread -v -D4 usb_get_paths about to look through devices: usb_check_and_add() called with VID 0x1d6b, PID 0x2 Get config desc. 0 failed usb_check_and_add() called with VID 0x971, PID 0x2007 usb_check_and_add() found known instrument usb_check_and_add() called with VID 0x1d6b, PID 0x2 Get config desc. 0 failed usb_check_and_add() called with VID 0x8087, PID 0x20 usb_check_and_add() called with VID 0x5e3, PID 0x608 usb_check_and_add() called with VID 0x5e3, PID 0x608 usb_check_and_add() called with VID 0x4a9, PID 0x1093 usb_check_and_add() called with VID 0x4a9, PID 0x10b1 usb_check_and_add() called with VID 0x1397, PID 0xbc usb_check_and_add() called with VID 0x1d6b, PID 0x2 Get config desc. 0 failed usb_check_and_add() called with VID 0x8087, PID 0x20 usb_check_and_add() called with VID 0xa5c, PID 0x21b2 usb_check_and_add() called with VID 0x408, PID 0x2fb1 Get config desc. 0 failed icoms: There don't appear to be any serial ports Connecting to the instrument .. munki: About to init coms munki: About to init USB icoms: About to set usb port characteristics icoms: About to open the USB port, tries 0 icoms: USB port needs opening icoms: About to open USB port 'usb:/bus0/dev1/ (X-Rite ColorMunki)' Opening USB port 'usb:/bus0/dev1/ (X-Rite ColorMunki)' config 1 failed (Operation not supported or unimplemented on this platform) (Permissions?) spotread: Error - Opening USB port 'usb:/bus0/dev1/ (X-Rite ColorMunki)' config 1 failed (Operation not supported or unimplemented on this platform) (Permissions ?) Best wishes Terry From: Terry Hewitt [mailto:w.terry.hewitt@xxxxxxxxx] On Behalf Of Terry Hewitt Sent: 14 October 2011 14:01 To: argyllcms@xxxxxxxxxxxxx Subject: Error open USB - Color Munki Photo - windows 7 64 bit Just installed ArgyllCMS 1.3.4 Trying to use it with my Color Munki photo. System is Windows 7 64 bit. I've installed the ArgyllCMS USB driver. (can see it correctly in Device Manager). Run as administrator a command window and then when I run spotread -v -D4 Connecting to instrument .. Spotread: Error - Opening USB port 'usb:/bus0/dev2/ <X-Rite ColorMunki'> config 1 Failed <operation not supported or u unimplemented on this platform> <Permissions ?> Any advice on how to fix or provide further debugging information please? It works successfully on my Windows 7 32 bit system. Best wishes Terry