I used to have onTrack Disk Manager on my Western Digital Drive. The software loads some code to overcome BIOS limitations enabling older PCs to support larger hard disks.
I don't think you can disable it; and you need to make a special boot up floppy disk with the necessary binary files on it. If you boot from a standard recovery disk you won't be able to access your hard drive.
Sorry if this is all a bit vague. I haven't used it for well over a year.