you have some damaged files. try this, it'll reregister the needed files, hopefully
then type the following (oh yeah, put in the windows xp cd but dont let it autorun):
expand D:\i386\config.nt_ c:\windows\system32\config.nt
expand D:\i386\autoexec.nt_ c:\windows\system32\autoexec.nt
expand D:\i386\command.co_ c:\windows\system32\command.com
Im assuming, by the way, that c:\ is the system drive (in case of dual boot) and the D:\ is the cdrom. Let me know if this works, there are other things you can do. I'll check technet to find some info then and give the hyperlink.