Writing "Zero's" to a HDD.

[tom43]

         There have been a few posts on this procedure. That said, I have not read anyone mentioning the 1st critical step of "Clearing the "CMOS" first. A few years ago, while sniffing around in the Microsoft "Knowledge Base", it was stated that to effectively zero or "low level format" a HDD, this is necessary. When clearing the CMOS, YOU MUST PULL THE POWER PLUG FROM THE WALL RECEPTICLE before removing and resetting the jumper or you will FRY your Mobo. LOL. Again, a few years ago, I forgot to disconnect the power first and FRYED the Mobo. Fortunately, EPoX replaced the Board for me. An example of clearing and not clearing is, with my Foxconn Socket 939 Board, when I have not cleared the CMOS first, upon completion of the procedure and starting to load the OS, the BIOS will alert me that I have made a modification. When I clear the CMOS first, I don't get this pop-up notice. Before I forget, with a Laptop, you pull the Battery to clear the CMOS. In my brief experience with Linux, only three years now, I have found that this procedure is a mandatory step to a perfectly clean and flawless installation. Also, and in summation, if you have either a Seagate, Western Digital, or Hitachi HDD, all three have a Diagnostic Tool that includes this feature.

[Was_Just19]

There have been a few posts on this procedure. That said, I have not read anyone mentioning the 1st critical step of "Clearing the "CMOS" first.

I would guess that is because the BIOS contents do not effect the writing of 'zeros' or 'ones' or a random combination of both, to any HDD, IMO.

when I have not cleared the CMOS first, upon completion of the procedure and starting to load the OS, the BIOS will alert me that I have made a modification

You are confusing the BIOS contents with the OS.
The BIOS will inform you that it has incorrect information stored .......  it is a simple matter to correct that, by entering the BIOS and making the edits.
At that point the OS has not started.
"Clearing the CMOS" will eliminate any previous edits to the BIOS ......  not recommended for most circumstances.

I have found that this procedure is a mandatory step to a perfectly clean and flawless installation.

Not clear what procedure you are referring to here ......  pulling the battery, clearing CMOS/resetting the BIOS, or completely overwriting the whole HDD.
In any case I have not found it necessary to 'zero' out an otherwise healthy drive just to install a Linux OS.
Resetting the BIOS is usually necessary only in exceptional circumstances IMO - for instance if it has become corrupted.

That is my take on the situation ..... of course I do not have a Win install and do not read any of MS's blurb!   

Other's may have different views of course   

regards.

[Old-Polack]

I'm with JohnBoy on this one. I have no idea what crap Windows my try to write to the BIOS, or seek, if anything, in the MS "marriage" of the OS to the individual hardware, but this is a totally unnecessary, and possibly dangerous, process when simply zeroing a hard drive.

I've zeroed dozens of drives, (possibly hundreds) on dozens of machines, and never once had need of such a thing. Zeroing a drive simply purges it of stored information, restoring the platters to like new condition; a blank slate. Partitioning and formatting are done as with any new drive.

BIOS involvement is only to recognize the presence of the hard drive on whichever controller it is connected to, and whether or not it contains MBR boot code. What boot code it may contain is of no interest at all to BIOS. The partition table layout and formatting are of interest only to the installed OS.

[menotu]

I concur with both JohnBoy and old-polack

In certain circumstances clearing the CMOS has so many potential hazards it doesn't bear thinking about 

[DrDOS]

I  too concur with both JohnBoy and old-polack  And I've written many a drive to zeros, two just this week.

However, that being said I would like to make a couple of cautions here. Some machine makers, on older machines, and some drive makers, put part of the BIOS or drive firmware at the start of the hard drive, in the first couple of sectors after the boot sector. When you write the drive to zeros you remove this and have to replace it. But this is rare now, you will only need this information if you encounter a problem after writing the drive to zeros.