Laptop Hangs on Boot - Fix

I was working at home this past weekend and found a very frustrating bug.

On the weekend, I connected my company Dell Latitude E4310 to a second analog monitor using the internal VGA port after booting. Worked just dandy. End of the day, did a shut down, disconnected from the VGA.

Went to work on Monday, put the Dell back into its dock, started it up and it hung on startup - no error messages, nothing, just the Windows 7 startup splash screen with no activity. There was a big Microsoft download going on, so I waited, knowing the network was creeping along with all the users being updated. 2 hours. (I did try a restart after an hour, no help.)

Pulled it out of the doc and tried a restart alone, with success. While it was running, I plugged it back into the dock with no further issues, and it connected as normal to the external DVI monitor connected to the doc.

Yesterday, working at home (after a dentist’s appointment – not recommended), I started up the Dell again to begin work, but not attached to the second monitor. It hung on startup. Once again, no error messages, nothing.

Finally, after about an hour of F8, safe boot, safe boot to command line, everything I could think of, no boot. Just hangs on startup.

Checked Google… Saw an obscure forum post about hanging with two monitors. Naw, couldn’t be. Yep!

Plugged in the second monitor into the VGA port while it was off, and then she booted right up.

After I finished working for the day, I unplugged the second monitor, did a shut down, tested a startup, and it booted cleanly. It also booted cleanly at work in it's dock, and did automatically detect my second monitor.

The fix is to disconnect from a second monitor connected to the internal VGA port before doing the shut down.

Oh, and talk to the Dell team in charge of maintaining the POST code. ;-)  If power up hangs waiting for a second monitor, exit the loop and go to single internal monitor mode, as it does for a DVI monitor coming in from the dock!