Make external monitor Primary
I had to trick the machine by 1st disabling the original primary monitor (as if you only had the 2nd monitor, similar to using a laptop that you want to close). On my IBM thinkpad/laptop, I did this by pressing the blue Function key on the keypad and F7 at the same time, which is the split screen display quick-key for IBM (on my old dell, there was a function key to send the screen to an external monitor as well). Pressing this shuts off the screen on my laptop (goes totally black on the laptop) and everything appears on the external monitor, since it is the only monitor and now primary. Then on this working external monitor, go to start>Control Panel>Display>Settings>, highlight the grayed out non-working #2 monitor, check the box to "extend my windows desktop onto this monitor", then hit "ok". The 2nd monitor should now be your secondary monitor with the "primary monitor" being the external monitor.