What can I do?

[kieronm]

I restarted my Mac Air with OS X and was faced with a grey screen and a spinning wheel. I suspect (and only suspect) that I don't have enough memory for my MAC to re-start. I've managed to get into disc utility by running disc 1 of my CD, but because there isn't enough space to re-install OS X it is saying that it will need to erase my HD which would be a mare as I haven't backed up for ages.

Any help would be appreciated.

Mac Air Mac OS X (10.5.6)

 

[r.j.s]

Insert the DVD and hold D while booting to run a hardware test.

 

[kieronm]

Insert the DVD and hold D while booting to run a hardware test.

Did that and ran a standard test. 'No trouble found'