Sometimes when booting off an install disc, it does take a few minutes to advance to the next screen. How long did it seem to be frozen? If it is frozen, then look at the disc, and see if it's scratched or smudged. Try cleaning the disc with a soft cloth, and then retry.
Another option, is to just try to remove the software that has infected your computer. There is a malware guide in my signature for doing just this.