permissions verification

I am new to this site, and am not sure where to look for the following...
My macbook stopped working yesterday and ended up with a flashing '?' in a file logo. My small instruction book said put installation disk 1 into the computer and go to disk utility to select disk repair. I tried to do his but the only thing I could select was verify disk permissions - then it said first aid failed because there were no valid packages. I had selected the hard disk icon - but maybe it didn't recognise it? I just want to know what to do next... do I reinstall the system software? I am worried, as I have work on the computer not backed up! I use the macbook quite a lot, so was wondering if the computer had over-heated? I hope somebody can help...
One thing, I checked the hardware - and that seemed to be OK. I had to choose a prefix - because the computer isn't working I'm not sure if it's 10.4 or 10.5 (as you can tell I'm not good with computers!)

did you strat up the mac from the install disc, by pressing the C key on strat up.

If the mac boots from the CD (you will not see your usual desk-top, but can still select disk utilty from the top menu), then disc utility will be able to repair the disc.

Try that first

is it an intel or PPC mac by the way

Hello,

Thanks for replying.
I did start up from install disk 1 pressing C. In the disk utility it would only let me verify disk permissions. I selected the hard disk and clicked the verify disk permissions - then it said first aid failed as there were no valid packages...
It's an intel machine. Regards, John