Hi guys,
I have a C project under IAR IDE which I compiled et rebuilded without any errors.
When I try to download it to Arduino, JTAGICE mkII raises that error:
FATAL ERROR : failed to initilize USB driver (internal system error)
error 0x20000007
I already secified my target device and don't know what can cause that error !
Thanks for any help 
Problem partially solved .
Jungo connectivity (USB driver) wasn't installed with IAR IDE so I had to install it myself. Now I got another error :
USB device not found or already in use.
There should be some configuration to be done but I don't know what it s or where to do it. Even in the IAR manual doesn't help.