After i installed vista my screen size is much smaller. It dosne't fill up my whole monitor .How can i fix it

I've done everything from restarting my computer wiht everything plugged out to changing the screen size. It still dosen't fill up the monitor like b4, when i had xp. Ther's a big thick black border around my desktop now. Please helpAfter i installed vista my screen size is much smaller. It dosne't fill up my whole monitor .How can i fix it
If you mean there is a black-ness around the actual desktop that is because your monitor is not configured correctly. You should see some buttons on the bottom left of your monitor (the actual physical monitor, not the screen), depending on your monitor brand.

There should be a button that acts like a menu. When you push it a menu lookin' thing should pop up on your screen. Find the that look like two arrows pointing horizontaly. Go into this by pusing the menu button again. Now use the increase and decrease buttons on your monitor to make the screen wider. When it is the right width, exit out of that by pressing an ';exit'; button on your monitor. Now find the thing on the screen that looks like two arrows pointing vertically. Do these same steps until your screen fits the size of your monitor.After i installed vista my screen size is much smaller. It dosne't fill up my whole monitor .How can i fix it
If you have a lcd screen, change the resolution to the native one for the monitor. If CRT, do what it says above.