Atmel Flip not working

I am currently trying to create a macro keyboard with an Arduino Mega 2560.
Therefore, I have to flash the Arduino with the Atmel Flip software.

My problem is, that there are two different errors:
Either it says that it can't find the file "AtLibUsbDfu.dll" or that that it can't open an USB device.

Is there anybody who has an exact description what I have to do, maybe from the very beginning (installing board drivers, because I don't really know if I have to install drivers that come with the software or the driver that I was using before i had installed Flip).

I would really appreciate if someone could help me.

Keep in mind the context. Flip and any other DFU means of updating 'firmware' is dealing with the USB serial converter chip that is implemented in a 32U (or other USB capable avr chip). This is not directly involved with how one programs the main AVR chip on the board, a 328p in the case of a Uno board, which is either via USB serial interacting with the bootloader code in the 328p, or via ICSP without needing a bootloader.

Only very very very very few arduino users ever have a need to upload new firmware to the USB serial chip.