Major Resolution Problem

I'm not very good with computers so please be gentle. I got my Dell about 2 years ago. Ok, I have a 4550 with a E151FP monitor and GeForce4 MX 420 card... now I'll get to my point. I set it up and at the time the screen res was set at 800x600 and it looked fine. Last July I dedcided to try out the 1024x768 and a few weeks ago, due to some older games, I decided to switch back to 800. The transformation was awful and not what it was before. The text is huge, thick and blurry/faded and my windows are gigantic. Someone told me to adjust my display from the advanced appearance menu from my display properties and all that did was make the text smaller, and yet it was still thick along with the icons. So I experimented with my adapter and every res looked horrible with the exception of 1024.

So then I emailed Dell and they told me I had to update my graphics card and that should solve it. Unfortunately the link they sent me kept sending me back to the support page so I checked for a GeForce download and all I found was an outdated one. I checked Nvidia and and all they had was the one I downloaded in December. So I guess I'm current with my updates (I hope). So now I'm still stuck as to how to fix this res problem. I hope... no I pray that someone has a solution that doesn't require me to send multiple emails constantly explaining this. Thanx