I've been experiencing a number of problems with setting up an external monitor as a primary display not a major issue but certainly one that causes me a headache every few days.
If I've plugged in my monitor as 2nd display which i've dragged the task bar across and i use as my main monitor i get some real hassle when i disable it and go back to the screen on the mini. The biggest problem is that the master volume control box won't come up on the mini screen. So then i have to reinable the second monitor and hunt for it by moving the monitor around in display settings and dragging it back to the mini, it's a real pain in the arse.
The other problem i've come across is that when i sometimes boot with the second monitor plugged in it boots as primary and then oddly disables itself and the mini screen comes up. Then all the display settings for which is primary and secondary are mixed up also the relative monitor placements are reversed.
Another thing i have noticed is that sometimes if i boot as primary on the external is that if i change the resolution it sometime goes nuts turns off and goes back to the mini screen. As for the Fn 4 switch well with all the other problems that scares the crap out of me lol as it compounds problems if used.
Normally i wouldn't really but to bothered to much but i use mikogo a piece of software for others to remotely view my screen and the other apps i use are too big to be displayed on the dell mini screen hence my need to set the external monitor as primary. It's not that it can't be done, i've sorted out a few times now but it's such a royal pain in the arse with so much messing around and three or four reboots before it's sorted various messing around with resolutions and so on.
If any one has any solutions or suggestions i'd be most pleased to hear them as its a twice weekly nightmarish chore for me to sort everything out and a ritual i could well do without.