my screen shrunk

ok heres the thing i have been trying to play oblivion forever and well i had a 128-pci card which is the minimum so i bought a 256-pci (geforce fx 5500 OC(what exactly does the overclock do with the card and how do i access it?)) well anyway after a really bad first attemp to get everything installed right(i have no idea what happened)i finally got it set then i did an extensive cleanup on my computer cause the card came with window washer and system mechanics well all in all after i completey flushed everything out of my computer i decide to mess with the settings so i put the resolution up to
1024x758(i think) and now my screen is like smaller....like it shrunk....and i know that when i set a higher resolution that the font and all that shrinks but my screen seriously got like a 2 inch black border.....how do i fix this?

ps..(oblivion still isn't working correctly......and i don't know why.....
req............what i have
512ram---512ram
p4 2.0ghz---p4 2.6ghz
128mb card---256mb card
xp---xp
if anyone knows why its not working correctly could you please help me out)

 

what type of monitor do you have, maybe the monitor doesn't support that high a res

 

This happens sometimes. There is usually a button on your monitor that brings up a little lo-fi menu which allows you to adjust features like screen size, brightness, contrast, or keystone. Use that to expand the screen size.

 

I gather you are running Windows XP? Right click on your deshtop. go to Settings, then Advanced, and set your monitor at a higher MHZ. If running XP it should only show MHZ that your monior can use. My monitor is set at 85HERTZ but your monitor may require a lower of higher settong. Try that and see if it helps.

 

i'm pretty certain you will need a much better graphics card than an FX 5500. I have a 6600GT and apparently it will struggle with oblivion (although i've never tried to it run myself).
The OC will be already applied to your card, and just means that your core and memory clock speed is slightly higher than a normal FX 5500.
...
I've just found this on the VoodooExtreme3D forum:

I'm afraid your PC doesn't come close.