Pictures, Fonts, Graphics, Movies Look Crummy

I bought a new computer--a COMPAQ f756nr notebook PC--and Vista was pre-installed. I connect to the internet via wireless modem and use cable internet connection. Everything looks terrible to me versus my old laptop computer--a Toshiba--and my old system, XP. I brought my computer back to Best Buy and the Geek Squad reps there looked at the computer and told me it was fine, just the way Vista looks on a computer and I should get used to it. Since I got this computer last week, I'm absolutely miserable and don't know what to do. I used to watch tv shows on my computer and email pictures but everything looks so bad.