Monitor Issues Post Re-Formatting

We have a Dimension 4500S and an E551c monitor.  I reformatted the entire harddrive recently and cannot get the resolution to adjust.  It won't let me go above 640x480 pixels under settings.  I searched the Dell sight for the appropriate driver and found it, but it's only compatible with systems up to Windows 2000 and Millenium--we have XP. 

 

I am a bit computer illiterate and am not sure if I'm installing drivers correctly so I need some coaching as well. (but it seems fairly idiotproof. :-)  I posted on this concern on a different thread, got chewed out for doing so, and then told to make sure I load the "Chipset Driver" first.  I have NO CLUE what that means. 

 

My question is, is it a compatibility problem with XP or am I just missing how to load this driver as new hardware?  I have it saved to the desktop and it "successfully unzipped all 5 items" but from there I get nowhere.  Under "advanced" option on the settings, the "properities" button is not activated.  That's where I get stuck.

 

Please, provide simple directions with some places to go for downloads and how to upload the programs and make them work.  I'm not a computer tech and wouldn't be asking these questions if I didn't know what to do first.

 

Thanks!

Andy