Graeme, There is good news and bad news... Tried you various suggestions of removing/re-installing driver/reboot. Still doesn't work. Tried stopping the two X-rite services - still doesn't work. The GOOD NEWS a) Tried a different USB port, ARGYLL usb driver, stopped the two X-rite services . b) IT WORKED!!!!! (I've had this problem with another device a Behringer BCF2000 midi controller - sensitive to which USB port I'm using. That seemed to also object when I plugged it in through an external hub. Maybe the same problem here, maybe not). The BAD NEWS. If I run spotread a second time it gives a panel which says "spotread.exe has stopped working". Then 3 options: a) Check online for a solution & close the app, b) Close the program c) Debug the program Problem details: Problem signature: Problem Event Name: APPCRASH Application Name: spotread.exe Application Version: 0.0.0.0 Application Timestamp: 4e5e4607 Fault Module Name: msvcrt.dll Fault Module Version: 7.0.7600.16385 Fault Module Timestamp: 4a5bda6f Exception Code: c0000005 Exception Offset: 0001a6ae OS Version: 6.1.7601.2.1.0.256.1 Locale ID: 2057 Additional Information 1: 0a9e Additional Information 2: 0a9e372d3b4ad19135b953a78882e789 Additional Information 3: 0a9e Additional Information 4: 0a9e372d3b4ad19135b953a78882e789 Read our privacy statement online: http://go.microsoft.com/fwlink/?linkid=104288&clcid=0x0409 If the online privacy statement is not available, please read our privacy statement offline: C:\Windows\system32\en-US\erofflps.txt If I delete the cmd window, create another one spotread works the first time, but not the second time! At least now I have a work around for what I want to do. Thanks for the help. If you want to do any further debugging happy to help if you give me instructions. Best wishes Terry From: Terry Hewitt [mailto:w.terry.hewitt@xxxxxxxxx] On Behalf Of Terry Hewitt Sent: 17 October 2011 13:09 To: argyllcms@xxxxxxxxxxxxx Subject: [argyllcms] Re: Error open USB - Color Munki Photo - window Graeme, It looks like I have the Argyll USB driver loaded for my Color Munki Photo. Let me know if you need anything else. Best wishes Terry