Hi Harvey of D_Bay,
When your computer does not display anything on the monitor you may have a No Display or Blank Display problem. This can be caused by any of the following reasons:
• Monitor or System has no Power
• Monitor is defective
• Loose VGA/DVI Cable Connection
• Video Card Problem
• AGP/PCI-e Connector Problem / Motherboard
• System RAM Problem
Method 1: First, update the drivers for Graphics card and check.
Method 2: Duplicate the display settings and check if you can view the Screensaver in the extended monitor as well.
To change your display settings to extended
1. Open Screen Resolution by clicking the Start button, clicking
Control Panel, and then, under Appearance and Personalization, clicking Adjust screen resolution.
2. Click the drop-down list next to Multiple displays, click
Duplicate these displays, and then click OK.
The Multiple displays option appears only when Windows detects more than one monitor connected to your PC.
Note:
o If you don't see an option named Multiple displays in your display settings, then Windows isn't detecting a second monitor plugged into your desktop computer. Or, it is not detecting an external monitor plugged into your laptop. When Windows detects this
monitor, it will appear in the drop-down list next to Display. If you don't see it listed there, try clicking Detect.
o Make sure the monitor you want to extend your desktop to is turned on and plugged into the correct video port on your computer. You might also need to select the correct source labeled on your monitor's controls to ensure the monitor is using the correct
video port. For more information, check the manual for your monitor or go to the manufacturer's website.
Refer the following link for more information:
Move windows between multiple monitors**http://windows.microsoft.com/en-US/windows7/Move-windows-between-multiple-monitors**
Method 3: Also make sure the screen resolution is the same on each display.
For more information, see:
Getting the best display on your monitor**http://windows.microsoft.com/en-us/windows7/Getting-the-best-display-on-your-monitor**
Note:
Some screen resolutions might not be available on all monitors because of differences in display hardware, electronics, video cards, and drivers.
Regards,
Divya R – Microsoft Support.