Can't get past gray screen on startup on Macbook Pro 13".

I have tried lots of things with this. When i boot it up, I can't get past that gray screen. I have tried using the utility disk, but it won't recognize the disk; it acts as if it isn't there. So I think it is a hardware problem. Can anybody please please tell me the best way to fix this????? Any help is much appreciated!!!!!!!!!!!!!

Try booting in Single User Mode and running fsck. The effect is similar to running Disk Utility from the CD. Directions can be found at http://help.sps.lane.edu/quickTips/pdfDocs/SingleUser_fsck.pdf starting near the bottom of page one