It always uses IE 7's rendering mode. To change it you need to make a registry change:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\MAIN\FeatureControl\FEATURE_BROWSER_EMULATION
or for a 32bit application on a 64bit machine:
HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION
set the keyname to be the name of your application executable then the value to:
11001 (0x2AF9) - force IE 11 mode
11001 (0x2AF8) - IE 11 mode
See Rick Strahl's blog post for more information. This answer is based on that.
If you make the registry change on your PC to force IE 11 rendering then give the application to someone else their PC will use IE 7 rendering unless you make the same registry change on their machine.