My laptop no longer hooks up to the monitor correctly.?

In addition to connecting up the monitor with the VGA cable and the power, you often also have to tell the operating system that you have a second screen, and to make use of it. Normally if you right click on the desktop and select properties - you will get to a screen where you can specify how your monitors are oriented and tell it to use both of them, or even just the external. I would check that first, before assuming a hardware problem.