Funny thing with my Dell Latitude D620 with an Nvidia Quadro NVS 110M.
I reinstalled Windows XP the 3rd time now and I'm always having the same issue:
with the newest driver installed it's impossible to extend the Windows Desktop to an secondary Screen or duplicate or switch to it- the software doesn't recognize the external CRT. With an older version of the driver everything works fine. Needed some thoughts to recognize that problem though. I'm just sharing this perhaps I'm not the only one with the problem.
good old driver:
Release Date: 12/11/2007
Version: 156.83-xp WHQL, A05
bad new driver:
3/26/2008 174.31 WHQL A07
PS: wanted to post this in the Dell Forums but the registration of the username is a pain, in particular the password ...