00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 18)
02:00.0 VGA compatible controller: nVidia Corporation Device 0df1 (rev a1)
There are 2 video chips on your laptop. In windows, they are used to switch between two when using 2D/3D/HDMI. Unfortunately, it confuses ubuntu driver installer, resulting in broken X server. After fresh ubuntu install, it is likely that Intel chip is used. However, HDMI output is controlled by nVidia chip. The solution i can see is to disable Intel chip in BIOS and use only nvidia with drivers installed. This should enable HDMI but likely to kill battery life of laptop/produce a lot of heat. I came across this blog with very similar problem: http://www.enavigo.com/2010/05/29/nv...d-ubuntu-fail/
These hacks will have a good chance of breaking your install, as you've stressed, its a work laptop, back up and be prepared for complete OS reinstall if things go wrong.