well... i knew that i forgot to mention something :rolleyes:

the driver is not the problem (works fine with my W810 & D750 @ W800)
i tested it on every USB port... just nothing happens :( (edit: with the z550)


and for the battery... it's not my first SE to flash ;)
i already flashed like... 30 phones or so..

but those 2 (Z550 & K750) just drive me crazy

nothing works :(
and i don't know why ..