screen resolution too small

i just re-installed windows xp pro on my dell optiplex and the screen resolution is too small to run any major programs so i tried to fix it by right clicking on the desktop and selecting properties and clicking the settings tab and the slider that changes the screen resolution won't move at all

and there are special programs put out there to change the screen resolution but when i used one the color came out weird (it was probiably less than 32 bit now)

 

What does re-installed mean ?
- Format and fresh install ?
- Using the XP CD that came with the PC ?
If not, did the PC come with some other OS ?
Have you gone to the Dell web site, and downloaded all the XP drivers for that model ?

What does too small mean ?
You cannot read it because the resolution is too high ?
Or ?

Why not take a punt, and give us as much info as possible.

 

I get that most times when reinstalling XP Pro.
I run Windows Updates and go through the Optional Software portion.
Usually gets corrected.