EzBios removal

2006/06/11 by Lassi A. Liikkanen

Removing Ez-Bios

Ez-BIOS is a software used with older computers (386, 486 and Pentiums). It intends to trick computer's BIOS so that operating system can access hard drives over 2 GBs (believe it or not). You will not find this software anywhere on your filesystem, it is stored in totality to the normally unused space in the hard drive's first track, called zero track. The same track contains also the Master Boot Record or MBR. Ez-BIOS shows up as you boot the computer after normal POST and BIOS checks and before OS gets loaded. While Ez-BIOS is not necessary for computers manufactured in this millennium you may end up situations when you want to remove the Ez-BIOS. I myself tried to install Linux based router package Smoothwall on an old Maxtor 10GB drive but failed to get LILO working while Ez-BIOS was still installed. I'm currently unaware of any similar Linux loading problems, but I assume that this same problem might bother also other distributions.

What does NOT help

I first tried to format the drive using MS-DOS 7 format. While this effectively empties file allocations and clears the partition, it leaves the zero track of the hard drive untouched, or so I've been told, and therefore does not help.

I then installed Linux (LILO) to it. This killed Ez-Bios only partially as it prevented it from loading, but did not either load LILO and Linux. I have not yet found out whether this is a LILO bug, incompatibility or problem specific to the Linux distribution used.

Google's top 2 tips tell you to use either Bootmaster or Western Digital's Disk Diagnostic Tools software to disable Ez-Bios. Both programs are available for a free download. While the former can reliably confirm the problem the demo version will not fix it. WD's software might fix the problem if your drive is a WD, otherwise it will not co-operate unless you buy a commercial version of it. So neither of them actually provides any relieve for free.

The fix

The MBR must be overwritten in some way. My drive was empty and so I choose to do this by installing MS-DOS 6, but I assume that you will achieve the same effect with FreeDOS available as freeware. Note however that this may cause serious problems or be altogether impossible if you have some data on the disk. If the MBR is erased, but not fixed, your drive will not boot before some boot loader is installed in MBR. While this should not mess up the file allocations, I definitely recommend using Bootmaster or similar program for the procedure just for Your data's safety.

After the MS-DOS had successfully overwritten the MBR and therefore killing Ez-BIOS, I managed instantly to get LILO working.


The author takes no responsibility for the correctness of the provided information and all problems and tips should be considered purely fictional. The author strongly advises the reader to cease to take any action based on the content of this page and wishes to remind that serious material, physical or mental damage or may result if any of the instructions are carried out. Most Internet content is just plain stupid and/or dangerous, please consider all provided information before proceeding.

Keywords: [computers] Document's status: Ok (Document dates explained)

This document created: 2006/06/11
Modified: 2006/06/11
Published: 2006/06/11

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