- connect your ipod touch, ipad or iphone to the computer
- turn off the device
- press the power button (for 1-3 seconds until apple logo appears)
- once you see the logo, keep pressing the power button, but also press the home button within 10 seconds.
- keep home and power button pressed for almost 30 seconds (until the apple logo disappear), then release the power button but keep holding down the home button for next 30 seconds or so
This way you can enter dfu mode easily on your apple device.
DFU mode is needed when you are making changes to the firmware of the apple device.