My XP Pro system has gotten confused about the drive letters (and maybe more than just the letter) for the CDROM (HL-DT-ST DVD-ROM GDR8163B) and DVD drives. - Its a very long story. One result of this is it thinks my CDROM (M drive) is now read only - I can no longer use it for backups. I've been debugging my problem for about five months. The other day I thought I'd try to reload/update the driver. I downloaded a more recent driver from Dell and ran it but I get an error. During the pre-flash verifications, it passed FW model name, FW protocol, check sum, and drive model name. It failed at Drive Protocol and says its unknown. So how can I install a new driver? Actually what I think I really have is a problem in the registry or some other configuration file. I have run SystemWorks but I doesn't look for the tough stuff. Is there a great registry checker? Or is there a way to have the registry remap all the drives or totally clean out all reference to these drive and start fresh?