Unable to find operating system... Windows XP

Last night I came home to my kid using my laptop for games... CBBC Website.

He stopped using it for a couple for hours but left the window and laptop open.
When it came to shutting it down, the laptop had frozen, the mouse would move but not select anything.
I had to hold the power button to switch it off, and when restarting it says Unable to find operating system.
There are a few other error codes but I can't remember exactly what they are.
The laptop had been freezing recently but I referred to a recent good configuration and this seemed to rectify the problem.
Are there any suggestions to fix this?

Many Thanks
Steve

PS - Apologies if this is in the wrong forum area, feel free to move if required.