Inspiron 5100 Monitor Resolution??

Hey guys, just found these awesome forums, and as this is my first post I just wanted to say that the Inspiron 5100 that I bought from my friend is my absolute favorite PC that ive ever had... Ive never had one problem with it, no overheating issues as some have had in the past or anything else... but I just found out that I have a 15" Monitor on this thing, which is SXGA+ which is capable of 1400 by 1050 resolution.. However in the display settings page, I can only go up to 1024x768 which isnt a problem, but on some pages, such as these forums, I have to scroll around a bit to see everything on the page.. and Im a moderate gamer, I play CS:S and HL2DM and UT2004 and WoW alot and on all of those games i have the settings maxxed out, but having a higher resolution would make the picture even better. I have been searching for monitor drivers with no avail.... I dont even remember me even getting drivers for any of my old desktops, as this is only my second laptop [my first was a Dell Latitude CPiR which i just gave to my friend, and i didnt really care too much about the resolution on it. lol] But this system runs like a dream in those games i mentioned above, and so a higher resolution would be nice if possible.. How do I choose my correct display and resolution for this?? Thanks!

BTW here are my specs:

Inspiron 5100

P4 2.4 Ghz CPU [soon to be 2.8 Ghz w/ 1MB cache]

512 MB RAM [soon to be 1GB [My 16th is coming up in less than a month =]]]

ATI Mobility Radeon 9000 32MB----> with modded ATI Catalyst drivers... the ones from Dell arent too good.

30 Gig HD

15 Inch SXGA+ Display

Thanks guys!!

Richard