Have you tried re-booting? A "computer freeze" is usually a temporary thing.
It sounds like you want to re-install Windows, althugh you did not specifically say so. If you are determined to re-install Windows, the only way I know to get your license key from that disk, if it won't boot into Windows, is to connect the disk to another computer and use a license key finder program on it.
1) Is the un-bootable computer a laptop or a desktop?
2) Do you have a second computer to connect the boot disk to? If so, is the 2nd computer a laptop or a desktop?