I suggest that you take the easy route first, and re-run the install. If you have dual boot facility, search for tech spec of the monitor (if you don't have a nice fat instruction book for it).
Then you should (theoretically) be able to apply the manual setting of resolution and V and H frequency.
I usually have to do that with my Philps Brilliance 201B (a large business monitor that I got second hand).
p.s. Oh and if you system uses nvidia based graphics, you may still get a crappy graphical view untill you have the nvidia driver installed (again, I also have to do that).