How to reinstall my mac?

Question

after loading some videos frm my sony cam into my mac.... the whole computer juz freeze.... so i had to restart it... (i restart it with the power button...) now my mac start with a '?' folder... n juz gets stuck there... i read some instructions frm the guide bk...now even the disk utility gets stuck in..."gatherin disk information"... n reinstallin the whole thing doesnt work!!!!

PLEASE HELP!!

Answer 1

Your Mac is still under warranty for any hardware problem -- however you will have to pay for software service.

First step is to start up with the OSX DVD (hold the "C" key down as you startup.) When you get to the installer screen, answer the language choice question, then on the next page, go to the Utilities menu at the top, and pull down to Disk Utility.  Choose the icon of your hard disk on the left, and then choose Repair Disk.  Give this lots of time to finish.  

If it successfully repairs the disk, then you can go ahead and do an "Archive and Install"  (NOT Erase and install). The Archive and Install will replace the OSX software, but keep your User account, Applications and Data.

If you cannot Repair Disk, or the icon of the hard drive does not appear in Disk utility, you may have a hardware failure.

If you buy the Applecare extended warranty for the machine (which you can do up to the 365th day) then you will get free phone support from Apple on OSX software issues.