1) Good idea, get latest video driver from
AMD/ATI.
2) From the windows crash reports, it's perhaps possible to know in which .dll or .exe the program crashed, this is very valuable information.
3) Try unplugging your "Logitech USB Headset"
4) Modify [your Steam directory]\steamapps\common\defcon\preferences.txt and set "ScreenWindowed = 1"?
(Is seems this defcon don't include dbghelp.dll for doing some nice crash reports,
looking at the defcon.exe from Steam version, the dependency was removed)