Cannot display this video mode!!!How to reset the resolution of pc. 

In case you accidentally changed the resolution of the screen and it shows like this..
For the first part..
Switch on the computer wait for the logo..
Suddenly switch off..then repeat it 3 or 4 times...
Untill the repair option comes up.
Click the advanced option...
Continue to watch. .......
Thanks for watching. ...
Hope your problem solved
...Be safe