How to configure a monitor before connecting it?

Question

The screen on my brother's laptop (running Windows 7) is cracked and completely unusable. He was going to use one of the extra VGA monitors we have until he can get it repaired or replaced, but the monitor does not become the 'primary' monitor when connected--his desktop (and the monitor settings window) are still on the laptop's screen. Pressing Fn+F8, which looks like it should be that 'change monitor' button, didn't do anything. He's been using the TV in my room, as it uses HDMI and does become the primary monitor when connected, but that's not a very practical solution.

And we have no other HDMI monitors.

And the laptop won't run the VGA monitor and the TV at the same time (it just ignores the TV).

How could we make the VGA monitor the primary monitor instead of the built-in screen, before connecting it? My first guess would be to find and edit the appropriate config file, but according to this question, it looks like multi-monitor settings are stored in the registry, and the format looks really confusing.

Answer 1

Usually, this is a simple matter. Check you laptop, left side of space bar for a "Fn" key. On most laptops the "Fn" in combination with one of the F1-F10 keys will change the primary monitor. It is usually F5 or F6. It should have a rectangle icon above the key in question.

It should toggle between: 1. laptop only 2. external port only 3. both

You need to hold the "Fn" key down the whole time and then press and release the key with the single/dual rectangle above it. If the first time fails push it a couple more times waiting at least 10 seconds between pushes to see if the monitor fires up.