Reformatting CD-R discs

[Guest]

How do I erase everything (mainly songs) from a CD-R disc? When I use My
Computer and open the file, there's nothing excpet 'Write These Files to CD'
in the CD Writing Tasks window.

 

[Merlin]

You don't. CD-R's are a once write media and can not be erased.

 

[Ronnie Vernon MVP]

How do I erase everything (mainly songs) from a CD-R disc? When I use My
Computer and open the file, there's nothing excpet 'Write These Files to
CD'
in the CD Writing Tasks window.

You cannot erase a CD-R disk. It has to be a CD-RW disk. (Note the "W")
Which means that it is a Read/Write CD.

See the following article for help.

Burning CDs in Windows XP
http://aumha.org/win5/a/xpcd.htm

and

Primer on CD-R
http://www.mrichter.com/cdr/primer/primer.htm

Ronnie Vernon
Microsoft MVP
Windows Shell/User

 

[Vanguard]

How do I erase everything (mainly songs) from a CD-R disc? When I use
My
Computer and open the file, there's nothing excpet 'Write These Files
to CD'
in the CD Writing Tasks window.

A torch works well to burn it up. Some are so cheap that all you have
to do is crack the plastic disc in half and peel off the foil. CD-R are
not erasable. You get to write once. You have multiple sessions on the
CD-R so you can fill up the unused space. Each session will have a new
TOC that replaces the prior one to reflect the new content in the new
session which might even pseudo-delete files in a prior session (the
files are still there in the prior session but removed from the new TOC
in the next session). Eventually you end up finalizing the disc so no
new sessions are allowed (or you run out of space for any new sessions).
At that point, you don't get to write to the CD-R anymore, and erasures
are also writes. Throw it away and start with a new CD-R disc. They
are damn cheap (12 to 25 cents apiece).

 

[Brian A.]

A magnet will do fine in erasing the CD but you can't use it anymore. If you see "Write These Files to CD", then they are not written to the CD yet, they are temporary files in limbo awaiting your next move.

If you want to write them to CD, any CD:
Insert a CD in the CD drive.
Right click in the open window.
Select "Write these files to CD" in the popup menu.

If you want to delete them, select "Delete temporary files" from the popup menu.

--

Brian A. Sesko { MS MVP_Shell/User }
Conflicts start where information lacks.
http://basconotw.mvps.org/

Suggested posting do's/don'ts: http://www.dts-l.org/goodpost.htm
How to ask a question: http://support.microsoft.com/kb/555375

 

[RobertVA]

A magnet will do fine in erasing the CD...

Floppy disk, LS-120 disk or Zip disk sure, but a CD or DVD(writeable or
not)? Please explain how any magnet is going to affect the dye layer in
a CD-R or CD-RW

 

[Brian A.]

I'm sorry, let me clarify that. A very powerful magnet will do the trick, it's know as degaussing.

--

Brian A. Sesko { MS MVP_Shell/User }
Conflicts start where information lacks.
http://basconotw.mvps.org/

Suggested posting do's/don'ts: http://www.dts-l.org/goodpost.htm
How to ask a question: http://support.microsoft.com/kb/555375

 

[Bruce Chambers]

I'm sorry, let me clarify that. A very powerful magnet will do the trick, it's know as degaussing.

It doesn't matter how powerful the magnet is, it cannot possibly affect
an optical disk. (And degaussing magnetic media doesn't require a
particularly powerful magnet, either; just an electromagnet that's
driven by AC current.)


--

Bruce Chambers

Help us help you:



They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety. -Benjamin Franklin

 

[Guest]

I don't think there is a powerful natural or man made (electro-) magnet ever
made or possible to be built that can possibly be powerful enough to ever
hope to erase or otherwise render a CD useless

 

[Brian A.]

http://www.periphman.com/degaussing/degaussers/1200cd.shtml

--

Brian A. Sesko { MS MVP_Shell/User }
Conflicts start where information lacks.
http://basconotw.mvps.org/

Suggested posting do's/don'ts: http://www.dts-l.org/goodpost.htm
How to ask a question: http://support.microsoft.com/kb/555375

 

[Brian A.]

It doesn't matter how powerful the magnet is, it cannot possibly affect
an optical disk.

http://www.periphman.com/degaussing/degaussers/1200cd.shtml

(And degaussing magnetic media doesn't require a

particularly powerful magnet, either; just an electromagnet that's
driven by AC current.)

--

Brian A. Sesko { MS MVP_Shell/User }
Conflicts start where information lacks.
http://basconotw.mvps.org/

Suggested posting do's/don'ts: http://www.dts-l.org/goodpost.htm
How to ask a question: http://support.microsoft.com/kb/555375

 

[RobertVA]

I'm sorry, let me clarify that. A very powerful magnet will do the trick, it's know as degaussing.

That's why a magnet, permanent or otherwise, won't erase or even corrupt
the data. Writable optical disks utilize clarity instead of magnetic fields.

Optical media doesn't use magnetic fields. Heat from the writing laser
changes a dye layer's opaquacy. Pressed CDs, including most retail music
and software CDs, don't even have the dye layer, utilizing the shape of
the surface between the main polycarbonate disk and the reflective
aluminum layer.

Zip disks and LS-120s however use optical means to align heads that use
magnetic fields to record and read the data, thus they are susceptible
to magnetic erasure like floppies, Jaz disks and hard drive.

 

[RobertVA]

http://www.periphman.com/degaussing/degaussers/1200cd.shtml

From the reference:

"Patented (pending) Micro-Machining technique completely removes
data-bearing surfaces and assures National Security Agency requirements."

Note the "Micro-Machining technique completely removes data-bearing
surfaces" part. "Machining" means that the reflective and dye layers are
being mechanically cut away from the top of the disk. The device would
have to cut through the label to accomplish that. The "data-bearing
surfaces" are too close to the top of the disk to make cutting from the
bottom very practical.

Also note the absence of any optical media from the "DEGAUSS STRENGTH
REQUIRED" table at the bottom of the page.

 

[Brian A.]

That's why a magnet, permanent or otherwise, won't erase or even corrupt
the data. Writable optical disks utilize clarity instead of magnetic fields.

Hmm, I'm no expert but they claim to do just that.
<quote>
The 1200CD/Optical Media Eraser & Declassification System degauss / erases and declassifies CD-ROMS, WORM CD, CD-RW, CD-R and other Optical Media.

Optical media doesn't use magnetic fields. Heat from the writing laser
changes a dye layer's opaquacy. Pressed CDs, including most retail music
and software CDs, don't even have the dye layer, utilizing the shape of
the surface between the main polycarbonate disk and the reflective
aluminum layer.

Zip disks and LS-120s however use optical means to align heads that use
magnetic fields to record and read the data, thus they are susceptible
to magnetic erasure like floppies, Jaz disks and hard drive.

--

Brian A. Sesko { MS MVP_Shell/User }
Conflicts start where information lacks.
http://basconotw.mvps.org/

Suggested posting do's/don'ts: http://www.dts-l.org/goodpost.htm
How to ask a question: http://support.microsoft.com/kb/555375

 

[Brian A.]

From the reference:

"Patented (pending) Micro-Machining technique completely removes
data-bearing surfaces and assures National Security Agency requirements."

Note the "Micro-Machining technique completely removes data-bearing
surfaces" part. "Machining" means that the reflective and dye layers are
being mechanically cut away from the top of the disk. The device would
have to cut through the label to accomplish that. The "data-bearing
surfaces" are too close to the top of the disk to make cutting from the
bottom very practical.

Either way, degaussing is performed with a magnet.

Also note the absence of any optical media from the "DEGAUSS STRENGTH
REQUIRED" table at the bottom of the page.

Yep, sure did and the heading is for magnetic tapes, not any type of disks. I also noticed before that:
<quote>
For higher coercivity media, four passes are often recommended – two passes, with a 90 degree rotation for the second pass, and then repeat the process with the media turned upside-down.
</quote>

It may take longer yet it gets the job done.



--

Brian A. Sesko { MS MVP_Shell/User }
Conflicts start where information lacks.
http://basconotw.mvps.org/

Suggested posting do's/don'ts: http://www.dts-l.org/goodpost.htm
How to ask a question: http://support.microsoft.com/kb/555375

 

[Bruce Chambers]

Hmm, I'm no expert but they claim to do just that.
<quote>
The 1200CD/Optical Media Eraser & Declassification System degauss / erases and declassifies CD-ROMS, WORM CD, CD-RW, CD-R and other Optical Media.

No, they call the entire assembly a "deguasser," but make it quite
clear in the text that optical disks are ground down mechanically.


--

Bruce Chambers

Help us help you:



They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety. -Benjamin Franklin

 

[Richard Urban]

Degaussing is the application of a magnetic field produced by alternating
current to "MAGNETIC" media. There is not a degasser made anywhere that will
"degauss" (erase) OPTICAL media.

And, I don't really care WHAT the manufacturer calls his process. It just
ain't gonna happen!

--
Regards,

Richard Urban
Microsoft MVP Windows Shell/User
(For email, remove the obvious from my address)

Quote from George Ankner:
If you knew as much as you think you know,
You would realize that you don't know what you thought you knew!

It doesn't matter how powerful the magnet is, it cannot possibly affect
an optical disk.

http://www.periphman.com/degaussing/degaussers/1200cd.shtml

(And degaussing magnetic media doesn't require a

particularly powerful magnet, either; just an electromagnet that's
driven by AC current.)

--

Brian A. Sesko { MS MVP_Shell/User }
Conflicts start where information lacks.
http://basconotw.mvps.org/

Suggested posting do's/don'ts: http://www.dts-l.org/goodpost.htm
How to ask a question: http://support.microsoft.com/kb/555375

 

[Vanguard]

Quoting added due to Brian's ignorance of using quoted-printable format
in submitting Usenet posts. Comments added inline.

"Brian A." replied ...

...

I'm sorry, let me clarify that. A very powerful magnet will do the
trick, it's know as
degaussing.

You can only degauss (randomize) MAGNETIC dipoles. Magnetism is not
used in optical media. Take an ink pen and write a blob on your white
shirt. Now try using a degauss coil on the ink blot. Any effect?
Nope. Now take an aluminum disk and put an ink blot on it. You get the
rest. I dare you to find a big enough magnet to forcibly mechanically
stress the thin aluminum foil layer that physically destory the disc?
The foil would be ruined and so would be the CD-R media. So why bother
with a planet-size degaussing coil when you end tossing the disc anyway
and start with a new blank one?

 

[Vanguard]

http://www.periphman.com/degaussing/degaussers/1200cd.shtml

--- REPLY SEPERATOR ---
(only required due to poster using quoted-printable format for Usenet
posts)

Now there is proof of gov't stupidity. Yeah, let's have a machine that
attempts to degauss a surface that doesn't use magnetism to store data
and then machine off the surface, too. Yeah, let's hang him, shoot him,
burn him and just for good measure then poison him. The unit you show
is clearly to degauss magnetic media and it uses machining to DESTROY
optical media (because magnetism isn't used).

Machining off the foil would be sufficient, just like burning it would
be just as effective. You are physically destroying the disc, not
erasing it. The degaussing is NOT to erase the media. It is to so
mechanically warp the foil that it cannot be read from or written to
thereafter. Magnetism is not used to record the data, but magnetism
(alternating, that is) is used to physically stress the aluminum so
whatever technique that is used to encode the data can no longer be
used. Weak degaussing that does not physically stress the aluminum foil
will do nothing to remove the data which does not use magnetism. Strong
degaussing that does physically stress the foil then makes it useless
thereafter - and that is NOT the same as erasure or reformatting which
presumes the media is still usable thereafter. Flipping magnetic
dipoles using AC current does nothing to alter the physical "pit" from
writing.

There is only one way that I could see that a degausser could erase
optical media: if it used such a strong alternating field that
alternated so fast that is flexed the aluminum foil at a rate fast
enough to cause thermal stress that would then emulate a fuzzy laser
that causes the dye "pit". Well, how does that differ from any other
way of physically distressing the disk to destroy it? Rather than use
heat, they use mechanical stress through magnetism by flexing the foil.
They aren't degaussing any magnetic media. They are using the magnetism
to destroy the film. Maybe. I doubt it. After all, when building
equipment to gov't specs, that doesn't mean you build logical equipment.

Reread the OP. The user wants to erase the disc, not destroy it.

 

[Jim Macklin]

A magnet will erase a floppy, but a CD-R has pits burned
into the dye layer. About 5 seconds in a microwave does a
nice job of destroying the surface. Have a small glass of
water in the oven to absorb the excess RF energy.


Be sure to watch in the window, the light show is fun.



A magnet will do fine in erasing the CD but you can't use
it anymore. If you see "Write These Files to CD", then they
are not written to the CD yet, they are temporary files in
limbo awaiting your next move.

If you want to write them to CD, any CD:
Insert a CD in the CD drive.
Right click in the open window.
Select "Write these files to CD" in the popup menu.

If you want to delete them, select "Delete temporary
files" from the popup menu.

--

Brian A. Sesko { MS MVP_Shell/User }
Conflicts start where information lacks.
http://basconotw.mvps.org/

Suggested posting do's/don'ts:
http://www.dts-l.org/goodpost.htm
How to ask a question:
http://support.microsoft.com/kb/555375




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