Windows 7: Windows does not recognize external display connected to a laptop

Hi Forum!



I have a HP Pavilion dm1z laptop. The laptop has a HDMI port. I am trying to connect it to my Samsung BX2335 display. The display has the DVI dual link port only. So I bought a HDMI - DVI adapter.
I have Windows 7 x64 on my laptop.
When I start the laptop with the external display connected, the picture is duplicated on both the laptop and the external display. But as soon as Windows starts, the picture will only be displayed on the laptop, 'Starting Windows' being the last picture shown on both displays.
After some investigation it seems that windows could not detect the external display successfully. In the 'Screen Resolution' window the external display is shown as 'Display the device on: VGA'.
It is impossible to view the properties of the external display, as the option is disabled, and the display is called 'Default Monitor'.
I tried updating the AMD Radeon Catalyst drivers, but this did not help. Tried to install the external display drivers, but these installed as the mobile device display drivers.

Any ideas to fix this are highly appreciated

I guess you've already played with the hotkey on your keyboard that's used to control which monitors are used for display, right?