Just got a, new to me, Dell optiplex 760 PC with windows 7 Pro

I want to use it with my Acer AL2016W lcd monitor which has an aspect
ratio of 1.6:1 (20" standard widescreen).

None of the resolution options match the ratio I need so when drawing
circles, they come out oval shaped.

Graphics are provided by intel Q45/43 chipset and claims to have the
latest drivers.
Intel driver website does not help, they have nothing more up to date
Acer tech support say they can't (wont?) help

I've tried a couple of websites that install a scanner and tell you that
all your drivers need updating but when I look down its suggestions
there are no new graphics drivers.

Before you say I need linux, save your typing time. I need it to work
with windows 7 Pro.

The monitor works fine under XP which offers 1440 x 900.

TIA
Bob