I know from reading here and there that the DVD 400i DVD burner from HP is really a Philips DVD8401 DVD burner, assuming of course that your device manager shows 400c... Now, I've also read that after a few updates the drive can be updated to BenQ's 822 firmware version, but what I don't see anywhere, or are too blind to see, is whether or not the drive becomes capable of burning Dual-Layer discs after its been updated to 822a.... Thanks for your help...
The only drives I have heard of being converted to dual layer were some Nec drives. Those that installed the dual layer firmware are having about a 50% failure when they try to do this. The 50% that didn't work killed their drives. I would think twice about trying this if it is true. Also the cost of dual layer blanks being from $10. to $15. each isn't worth destroying your drive taking that chance. Jerry