Cant get flat screen to be main screen on laptop

[Dalton92]

Hello,
Im running an Acer Aspire 5100 and trying to get my Sharp flatscreen to be my main screen.
Right now the laptop is using the main half cracked screen as it's main monitor, I want it to run on the flatscreen not the laptop monitor...BUT

I've tried everything i could think of messed around in the display setting, (Can't uncheck main monitor being the first one) the Fn+f5/f6/or f7 doesn't work.

Any advice would be great.

THank you!

 

[hang-the-9]

When you go to the display properties of the second screen, you don't have a "set this display as primary" button, or does it just do nothing?