I've been using an AVR Dragon for several years, first on Windows 7 x64, and I successfully upgraded to Windows 10 at the end of July. The AVR Dragon continued to work correctly under AVR Studio 6.2 SP2 (details below).
Friday evening August 28, I was using AS 6.2 + AVR Dragon with a target ATmega32U4 via ISP. After several successful programming sessions, AS suddenly no longercould access the AVR Dragon - I spotted an error regarding "license not valid" in one of the alerts. Note that around this time, I noticed an alert from Windows 10 that an update had been installed. This PC is an HP i7-4770 system, fast, with 16GB of RAM. There were no changes to the target fuses, voltages, etc.
See below; the same target and Dragon work fine on an old, slow Windows Vista box.
So of course I rebooted, uninstalled, reinstalled and generally spent over an hour messing around.
No luck. I can see the AVR Dragon in Windows Device Manager, under the Jungo node. Windows thinks the AVR Dragon driver is installed correctly and working; AS 6.2 simply does not see it as a target under any circumstances.
I fired up an old Windows Vista x64 machine, installed AS 6.2, and the Dragon works fine with the same target.
I'm guessing a Windows 10 update changed something how the Dragon is enumerated and AS 6.2 no longer sees it.
Has anyone else seen this?