"Want to see something cool?"
hit a key combination and brought up a command prompt over the gui that was installing Vista/XP....
"Whaaaaat?"
You can open a game of Pinball or Solitaire during an install. Sound appealing to anyone? That's what I call multi-tasking :) So Shift + F10 will get you to the command prompt during an install like the shot below. It works on XP as well.

It only works from the GUI portion and not the white text on blue background parts. I googled it and saw some speculation on using it to inject drivers or folders during your install.
MORE INFORMATION
In some cases, it may be helpful to have access to a command prompt during GUI-mode Setup for the purposes of troubleshooting, copying drivers, starting and stopping services, starting tools such as Task Manager, or other for other needs.
To gain access to a command prompt during GUI-mode Setup, press SHIFT+F10.
rahul dutt avasthy
To gain access to a command prompt during GUI-mode Setup, press SHIFT+F10.
rahul dutt avasthy