Disk boot failure please insert system disc and press enter. how to solve this problem?

everytime when i turn on my computer it would display disk failure message.i insert my windows xp disk in then press enter. eventually it would bring me to another error message: a problem has benn detected and windows has been shut down to prevent damage to your computer........ the whole page is in blue. please help me solve this problem!! the weird thing is when i insert windows vista disc in it ask to to install it,but xp disc doesnt work the same way>< please help me!!