I have a dual monitor setup and today i put Firefox on my second monitor to do some homework while word was on my main monitor. I closed Firefox while it was still on the second monitor. Now when i open it, it opens on to the second monitor instead of the main monitor. I have tried closing it on the main monitor, but no luck. Is there any way i can get it to open up on my monitor instead of my second monitor?

Next time, you might want to move your application back to the preferred monitor before closing out of it. Apparently, the OS keeps the settings of which monitor you drag the application to, even if you shutdown & restart the system afterward. Fortunately for you, you have continuous access to both -- primary & secondary -- monitors. What you need to do from now on is, make it a habit to move your applications back to your preferred monitor -- primary or secondary -- before exiting or closing out the application's window.