That's the million dollar question. There is no way yet to flash away DLOAD with the Qualcomm bootloader on the Nokia Lumia 800.guys still theres confusion in my mind..becuase i have got a lumia 800 with DLOAD on it..can i use this thing to do a full unlock& flash custom ROMs??
The reason for the problem is that the Lumia 800 with DLOAD does not offer many options to access the device. The only protocol to access DLOAD phones is MTPz, which is undocumented. You need MTPz to send system files to DLOAD Lumia 800.