DisplayPort Dosen't work when isntalling GPU driver

[AlohaX]

Hello
as a non native Speaker its hard for to explain, BUT. here is the story

 

i have a Quadro K600 GPU, i use the Display-Port to connect it to my HP monitor (D-P 1.1 and 1.2 are Supported).

now every thing works fine, OK the next step is installing the driver, since GPU is useless without a driver.

Downloaded the Latest Release, Installing. until here the Display-Port Works Properly.

now after installing NVIDIA Driver, it asks me for a reboot. OK i reboot. HP logo pops-up, Starting Windows (Windows 7) Shows up

when its over (Starting Screen). my Monitor says (Display is going to sleep).

from there the PC keeps booting (i can hear it). and the display stays as it is (Display is going to sleep / No Signal)

i cant use VGA or HDMI ports, since this GPU comes only with DP and that useless DVI. (i don't have a DVI cable and never seen one before)

my question is. is my GPU damaged ? or could it be the Display-Port cable ? since it says it is made in China.

 

what could be the problem ?

thanks you