I don't know if I remember correctly but you may have to remove device from your device manager and have your micro rediscovered when you plug it in a USB port so hopefully it will change.
No nothing has been changed, but my question is : it's enough cange the board.txt in the conf directory of arduino API and then compile and send my sketch or in unknown way for me send wich is in board.txt to the processor?
In there you will find a -DUSB_PRODUCT="Arduino Micro" option. This value is taken from the boards.txt file. I tested it. If your compilation message doesn't say your product name, maybe you don't have arduino micro, you have genuino micro or else. The script under Arduino micro has a few places for 0x8x37 which resulted from a fight between Arduino LLC and Arduino SRL an age ago. Make sure you look up your device manager for the EXACT product ID and change the corresponding info in boards.txt
If all fails and you're frustrated, go to USBCore.cpp, which is located here: Arduino\hardware\arduino\avr\cores\arduino\USBCore.cpp
Change the following lines at the beginning:
#ifndef USB_PRODUCT
// If no product is provided, use USB IO Board
#define USB_PRODUCT "USB IO Board"
#endif