I'm trying to upgrade my Xprotolab firmware on W7 so that I can try out the PC Interface. Windows finds the Xprotolab in DFU mode (in the device manager)?but when I try to select USB comms mode in Flip, I get the error message "The program can't start because libusb0.dll is missing from your computer ..." I have installed the USB driver from libusbx as per the instructions on your site. I have also tried updating the driver as per the Atmel instructions but the computer responds that I already have the best version of the driver. No joy. What next?

Are you able to put the device in Bootloader? Does the red LED stay lit?
When you put the device in Bootloader mode, Windows should ask for drivers. You need to install the drivers from the Flip folder (not libusb drivers).

I have tried multiple times to install drivers using the zadig program, with no apparent effect. Either it is not working or I am doing something wrong (for a beginner or an idiot, there is no such thing as "common sense" - you have to spell it out). I thought I had followed all the instructions properly./\r\n//\r\n/What I have done since, with some improvement, is as follows:/\r\n//\r\n/For "Normal" mode -/\r\n/* Downloaded libusb-win32 from sourceforge.net ( www.libusb.org/wiki/libusb-win32 ) /\r\n/* Used inf-wizard.exe in the bin directory to create and install a .inf file - The XScope (in normal mode) shows up in the Device Manager under libusb-win32 devices/\r\n/* The PC interface starts but says the XScope is not connected/\r\n//\r\n/For "DFU" mode -/\r\n/* Yes, the red light comes on/\r\n/* The XScope shows up in the Device Manager as DFU ATXMEGA32A4U under Universal Serial Bus Devices/\r\n/* When I try to update the driver from the Flip usb directory the Device Manager says I have the best available version of the driver installed/\r\n/* Flip will now go one step further and give me an option to open a USB connection, but when I click "Open" I get the following error: "Could not open USB device"/\r\n//\r\n//\r\n/

P.S. Everything worked under Ubuntu 14.04 - I had some difficulty locating a binary of the latest version of AVRDUDE. When I did, it programmed the Xprotolab perfectly well, and the XScope interface also appeared to be working well.

I'm glad that it is working. On Flip, the error "Could not open USB device" can occur if the correct device is not selected: ATXMEGA32A4U.

Mysteries abound - especially where Windows is concerned. I unplugged the 'scope, deleted the device in Device Manager and plugged the 'scope in again. Windows said it was installing a driver, and when it finished, lo and behold, the Interface was working properly. Miracle!/\r\n//\r\n/It seems that I always have to use the same USB port to connect the 'scope. Would that be right?/\r\n//\r\n/Flip still doesn't work, no matter what USB port I use. Yes I checked - ATxmega32A4U (not fully capitalised the way you have it)./\r\n//\r\n/