My mac has gotten really screwy lately, and I can't find any information on it's symptoms. I'll give you a quick run down of what it's done. Let me know if you need any more information.

At first it was often running fan very loudly and Chrome crashed a lot. I figured I was asking too much from a macbook air.

But today when I opened system preferences and tried opening "Network" the program froze before actually opening (it's icon bounced in the dock but no windows opened, it was listed as "not responding" under force quit). I used force quit to end it. When I tried opening up other programs one at a time under system preferences, including disk verify, they all did the same thing.

I tried to restart the computer but it froze at the grey screen. I pressed the power button off and on again, and when the computer turned back on the wallpaper had reverted to the original one (picture of a galaxy). The programs under system preferences are now running, but having a computer revert to the original wallpaper without me actually trying to reset the computer to a previous point in time makes me worry that something has gone very, very wrong with my computer.

Would anyone please hazard a guess as to what went wrong with the computer, and any solutions that I would be able to carry out? At this point now that system preference programs are running again, I've run disk permissions to verify and repair the hard drive.

And now my computer says Disk Utility and Finder are not responding. Wonderful.

I'm going to try to get to an Apple store soon and have the take a look, but any advice beforehand would be greatly appreciated.