Unable to Mirror Dell XPS 15Z's display on a HD TV

I have a Dell XPS 15Z laptop. I connected its HDMI port to the HDMI4 port of my Samsung Series 7 LED TV. Following are what happened.
The first time I connected them, it worked perfectly. I was able to mirror the laptop's display on the TV and play the sound also through it. It continued to work for 9 days. During this period the connection was changed from the LED TV to a slightly older LCD TV and there too it worked perfectly.
On the 10th day morning when I turned on the system, I found that the TV was displaying the desktop and the laptop's screen was only showing the background of the desktop.
I tried to troubleshoot the problem and after several attempts with the "PERSONALIZATION" menu and the "Fn - F1" key combination, I came to understand the following.
I am only able to "EXTEND" the laptop's display to the TV. The only options I get in the "Multiple Display" box in the "Personalization" screen are 1. Extend this display, Show Desktop only on 1 and Show Desktop only on 2 (1 being the laptop's display and 2 the TV. There is no option for mirroring (Duplicate)!!
When I used the function key sequence and chose "DUPLICATE". I got the same result as before - Desktop on the TV and balnk background on the laptop's display.
When I checked the "Personalization" screen, I found that there were three screens shown. 1&2 inside a circle with half portion white and the other half blue on one screen and 3 n the adjacent screen. On dropping the "Screen ID" box down I found 1 was the laptop's display, 2 was a VGA display and 3 was the TV.
When I dropped the "Multiple Display" box down I found the following options. Extend displays 1&2, Show desktop on 1&2 only, Show desktop on 3 only. Once again ther was no option to mirror (Duplicate)!!
I tried to fiddle with the parameters under the Intel HD video adaptor config screen and found that I couldn't change any parameter there.
I performed a system restore to the automatic control point of the last day it worked properly and the result was the same.
UNABLE TO MIRROR!!!!!!!!!!!!!!!!!
If any of you have had similar experience, please share your observations.
Regards,
Murrier1

 

Have you tried reinstall your video card driver?

 

The Nvidia control panel (not the Intel control panel) has a multiple screen configuration section. Try fiddling around in there.

It's different than the Win7 Personalization screen.