Monitor Help :(

[Andeey]

hey guys, so Basically when i plug the Monitor plug into my computer and Make it a duplicat of my screen, is just goes black, and i see some lines going down, Can anyone help me so i can start playing on my Monitor

[SugarD]

Check your resolution settings in Windows, and make sure it detects both monitors properly.

[Brian]

Depending on your graphical card, it may not be able to duplicate the screen, or extend it.
What graphical card are you using, have you installed all the graphical card drivers, and have you also played with more then one screen before (* if yes, have you re-installed windows/reformatted it between then and now). Also, does the screen work as a standalone?