So my computer monitor is not displaying clear at all?

Here's the story, i bought a 22in. Widescreen LCD monitor made by ENVISION for my computer. After while my computer became slow so i decided to do a clean install by wiping the harddrive and reinstalling Windows (xp home). That all went fine but now my big monitor will not display anything like it used to. Everything is all scratchy and stretched out. I noticed that it is running at a lower resolution than it used to but it wont let me increase it in Display Settings. It is a plug and play monitor so no CD or drivers came with it. I also don't have the original 17in monitor that came with the computer anymore. You can email me at mkivboost@hotmail.com if you have any info or just post here. Help is definatly appreciated. PS i am computer savy so dont be afraid to talk technical......(i also did the whole unplug and restart thing and nothing changed. THANKS IN ADVANCE!