And what exactly do you mean by a "reboot cd" I can only assume that you are talking about an installation disk that lets you boot from the disk and reinstall windows.
A disk like that should have come with your computer and should have been kept in a safe place. There are some other bootable disk utilities on the internet but nothing that is going to get you into windows with any kind of ease.
Can you please explain your problem in a bit more detail to us so that we can help you more?
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