Before you start, it is helpful to know what version you are currently running. While methods can vary slightly between HK models, for many AVR units, you can check the version by: Pressing and holding buttons on the front panel simultaneously. The current software version should scroll across the front display Step-by-Step Update Instructions
Harman Kardon AVR 151 Software Update Guide Keeping your Harman Kardon AVR 151 harman kardon avr 151 software update
Use a thumb drive formatted to FAT32 . Larger or differently formatted drives may not be recognized by the AVR. Before you start, it is helpful to know