Display issues

[nicomaga98]

So I just bought a 240hz monitor to connect to my 60hz gaming laptop. I plugged it in, changed my monitors refresh rate to 240hz and my laptop went black. I unplugged in and now my laptop has white and grey lines going through them. So I reset my laptop and its working now. My issue is, why does my laptop freak out when I increase my monitors refresh rate? I thought you simply had to plug a laptop into a monitor and the monitor would display 240hz from the laptop? I would try and mess around more with the settings but I dont want to ruin my laptops display without consulting with you guys first :) any help is appreciated thank you :)

[frankr2994]

Are you creating that refresh rate or is it listed to use for that monitor? Have you tried disabling your laptops display when you connect your monitor? 

[nicomaga98]

It is listed for the monitor, its a 240hz monitor