When no monitor connect , the resolution can only be 1920 * 1080 in 30hz?

I am using windows 7, and ati 7850 display card.

I would like to use the computer without monitor , and when I use teamviewer to control it, I found that the monitor detect is VGA , and the maximum resolution is 1600 * 1200 (60hz) or 1920 * 1080 (30hz).

Any idea about this? Since when I would like to use steam for game streaming it only let me select the 1600 * 1200, and there is no 1920 * 1080 choice, therefore, how can I set 1920 * 1080 60hz without monitor?

Thanks

Solution 1:

Are you connecting a monitor or a TV?

Below are some methods that could perhaps solve the problem, singly or several together :

Method 1 : Use a tool to force the resolution

Here are some command line tools that can change the screen resolution :
QRes, NirCmd, Display Changer.

Method 2 : Registry updates

Search the registry for DefaultSettings.XResolution, DefaultSettings.YResolution and BitsPerPixel and change to the desired resolution.

If necessary, add ColorDepth for RDP connection :

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services] "ColorDepth"=dword:00000003 in decimal.

More info can be found here.

Method 3 : Setting the video adapter to custom setting

If your VGA video driver has customizing software, you could do something similar to:

Method 4 : Use a fake video plug

If it becomes necessary to fool Windows into believing that a real monitor is attached, see this tutorial on how to create such a plug using a spare DVI-VGA adapter and three 68 ohm resistors: The 30 Second Dummy Plug.

Method 5 : Use PowerStrip (shareware, $29.95)

The PowerStrip utility allows you to gain complete control over the video card.
For more details see : Customize monitor resolution settings with PowerStrip.

Solution 2:

here is a copy & paste form this form:

First set desired resolution using:

ControlPanel → Display → Screen Resolution.

Also set ColorDepth using:

ControlPanel→ Display → Screen Resolution → Advance Settings → Monitor → Color

After this in regedit, manually search for DefaultSettings.XResolution, DefaultSettings.YResolution and BitsPerPixel and change all those to 1920, 1200, 16 (All in Decimal) respectively using next search button F3.
I also added entry of ColorDepth for RDP connection(not mandatory)::

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services] "ColorDepth"=dword:00000003 in decimal.

I don't know, which portion of registry did this, but now it works.