sounds like a corrupt operating system.
Call your local staples and ask them how to handle it. They may tell you to take it to them, and they'll fix it, or they might direct you to their warranty service (and often, this is the best bet... they're known for just replacing items with newer, faster models).
if you created the Vista CD's, you can recover your operating system (read the system manual).
If you did not, you can re-install Vista ONLY using the anytime upgrade dvd that came with the computer, and your vista code at the bottom of the laptop (some claim this doesnt work, i'm a tech, i do it all the time. it works). when you're done, you'll have to download drivers from Acer's website.
if nothing else, you'll have to contact acer (ugh!) and order new recovery disks.