Where is my neighborhood?

If it makes any difference, my computer if fairly new...as in I got it about a month ago and it has Windows Vista on it. Well, ever since I got my computer, it has a tendency to occasionally freeze and the screen will go black and a small square that is about an inch on each and has multi-colored lines on it will appear. The only way to get the screen to go away is turn the computer off. There have also been times when the stripes are large and grey and cover the whole screen.

Anyway, this has happened several times before when I was playing the Sims without any apparent consequences. But today I had just told my computer to leave the university and go back to Veronaville when my computer did the strange freeze thingy. Now Veronaville has completely dissapeared...I can't access it inside the game. Is there anyway to get it back? Almost all of my characters that I spend a lot of time on live in that neighborhood.

And I went inside my neighborhoods folder and it has G001, N001, N002, N003 in it plus, a tutorial micromanagement file.