Unable to boot

This is firstly not about my own computer, as I have a MacBook Pro, but it's a problem with my friend's computer, a MacBook.

It's a newly bought Macbook, with a age of just about 2 months.
I think her specs are:
Intel Core 2 Duo 2.0Ghz.
1GB or 2GB of RAM
120GB Hard Drive

She said she was working on her Mac (Firefox, MSN Messenger, Word, Finder, Skype and iTunes were opened).
Suddenly the computer froze. She switched it off afterwards and when she rebooted, she got something totally unexpected.
She uses Boot Camp to sometimes switch between OS X or Windows, but this time, nothing came up. I think that her Mac doesn't recognize the startup disc.
When she tries to reinstall Leopard, it says there are no editions of OS X installed.

Could this be a hard drive failure? Even though she only used it for 2 months with not a very excessive use? Any tips on what to try?

Thank you for reading and for any help whatsoever.

If you need any other details about the machine or what happens, please tell.

I would boot from the OSX DVD and run the Disk Utility from the Utilities drop down. See if it sees the drive. If not it sounds like the drive was defective and died. Happens. I had one new Seagate drive dead out of the box and another that failed SMART in minutes. Both brand new.

Try Disk Utility and see what happens.

Thank you, I'll tell her to try that.