Hi, I have a 5 inch Gps unit which is chinese, I only use it as GPS is it possible to delete the other functions so as to give it a little more memory. and is it possible to update firmware.
I would not do anything that you ask. Here's why. You may delete something that is necessary to the operation of your device and therefore just brick it. The least you should do is completely back-up the files/folders first before attempting anything. Secondly, updating firmware can be very dangerous. The slightest disruption of the firmware update could kill your device completely rendering it also useless. They can be done but it is not recommended.
Don't try it, I did and ended up with a brick. If you use Primo or IGo8 and have auto off working then you need never go back to the boot menu. The unit will auto power off and come back to the navigation application aqt the press of the switch.