I recently bought a VGA cable and VGA to MiniDisplayPort adapter in hopes of running a dual monitor setup using my MSI Gaming PC Laptop (Somewhere from 2011-13) and my all-in-one iMac. I plug the adapter into my Mac's MiniDisplayPort and plug the Female VGA cable into the VGA end of the adapter, then plug the VGA cable into my laptop. The iMac seems to register that I have a VGA cable plugged in, as its screen turns to blue the way it should, however, it turns blue then goes back to a functioning screen for a few seconds. when I look at my PC, all that seems to have changed is the screen resolution. it's still running Windows 7, still functioning like a PC should, just not registering that I have it plugged in. In my Mac's display settings it shows I have two screens going, but the PC laptop doesn't show it. Help? I'm running OS X Lion 10.7.5, if that helps. Any recommendations would be lovely. Thanks advance, Matty.