dpkg-reconfigure xserver-xfree86

[Doofus <doofus@bulldoghome.com>]

Can someone please tell me what `dpkg-reconfigure xserver-xfree86` 
actually does?

At the end of the procedure it talks about writing two new configuration 
files. Where are these files? I'd assumed it was talking about 
/etc/X11/XF86Config-4 but mine isn't changed in any way.

The reason I ask is I'm having an absolute nightmare of a time trying to 
get a X windows working on my laptop - a Dell Inspiron 8200 with 32MB 
nVidia GeForce2 Go graphics and a 1400x1050 pixel screen (which seems to 
be the real kicker).

xf86cfg prduces a sort of working config with a 640x480 display in the 
middle of the screen, but no mouse. Can anyone describe any other 
methods of fighting one's way toward a working config file?

Many thanks.