I merged an empty partition into my windows partition using partition magic. Now whenever i turn on i cant boot into windows. 

So i tried to repair windows but that didn't work and then i tried to install XP again on the same HDD (but not formatting it) windows loaded all of the files, but when it restarts, the HDD cant boot to finish the installation.
Does anyone know whats gone wrong or how to fix it, or is formatting the whole drive and re installing windows my only option?
Thanks for your help
So i tried to repair windows but that didn't work and then i tried to install XP again on the same HDD (but not formatting it) windows loaded all of the files, but when it restarts, the HDD cant boot to finish the installation.
Does anyone know whats gone wrong or how to fix it, or is formatting the whole drive and re installing windows my only option?
Thanks for your help