This item is from the Yet Another Enhanced IDE/Fast-ATA/ATA-2 FAQ, by John Wehman and Peter den Haan with numerous contributions by others. (v1.92).
This software is usually installed in the boot drive's Master Boot Record (MBR). Normal repartitioning and reformatting of the drive usually does not refresh the MBR, which can make for a frustrating experience. Fortunately, it's not very hard once you know how.
The best way to deinstall is to follow the procedure outlined in the utility's documentation. If this is not available, the following procedure usually works: boot from a clean floppy with at least DOS, FORMAT.COM and FDISK.COM on it. Then type FDISK /MBR. This should refresh the code in your MBR. After that, repartition and reformat as usual.
For reasons I do not understand, some Disk Manager versions are reported to cling to life rather tenaciously (perhaps due to overambitious virus protection by the BIOS?). In that case, you need DM.EXE. Type DM /Y-. If that fails as well, the following procedure was reported to work by Mark Brown (firstname.lastname@example.org).
1. run DM (in this case, v.6.03)
2. press ALT-T
3. select (D)isk Sub-System Overview
4. select appropriate hard drive
5. press CTRL-F10 to clear out the MBR
6. press Y to confirm
7. press ESC to exit out of DM, rebooting from a clean floppy
If you have faced similar situations and can add to this, please share your knowledge. A good candidate would be a utility that simply zaps the partition table---any takers?
WARNING. Disk Manager and EZDrive partitions differ from those created by a translating BIOS. Expect your data to be inaccessible after this operation. An exception is v7.x of OnTrack's Disk Manager; DM.EXE has a Migrate feature that works with many BIOSes.
WARNING. Some controllers and security software stores information on track 0 which FDISK /MBR will clear. In this case, the data on the disk is lost anyway, but there are a number of circumstances where this command can destroy data.