reoairing xp

Hi, I'm having problems with my windows xp, my computer won't even turn on, so I'm trying to repair using the disk. I've found out that my drive is not working, so I have to repair it using a usb. I tried making an image of the disk with my laptop, and i burned the image onto my usb. I turned the computer on and tried it, but it doesn't work. It has a bunch of writing going across the screen and doesn't change. Am I doing something wrong? How can I fix this? please help asap its very important.