RESOLVED: Please help me figure out this CD

[Deozaan]

UPDATE: I've come to the conclusion that the CD is corrupt (Cyclic Redundancy Check errors), and have told the owner to try to get a new copy from the original source. Original message below.


Someone handed me a CD, telling me it contains photos of her 5-year old daughter's ballet class. She says her computer won't read it and asked if I could get the photos off of it for her.

When I put it in my computer it tries to read it for several seconds but then gives up. It doesn't show up as having anything inserted in it.  Here's the mystery: I opened up the Disk manager to see what it would reveal, and it's showing this:

RESOLVED: Please help me figure out this CD

Media: CD-ROM Disc
Size: 1.1GB (1,073,741,312 bytes)
Volumes: 1.1 GB Unknown

The CD itself is labeled as a Philips 700 MB/80 min 52x speed CD-R. I'm sure most of those details about the CD itself are unimportant, but I included them just in case.

So... how can a 700 MB CD have a 1.1 GB partition on it? Is there any way I can salvage the data from the disc, or is it a lost cause? Any suggestions or troubleshooting steps I should take to try to get the disc to read properly?

Thanks!

[KynloStephen66515]

Have you tried to copy the files over via CLI?  If so, what happens?

[Deozaan]

Have you tried to copy the files over via CLI?  If so, what happens?

-Stephen66515 (June 07, 2017, 10:43 PM)

How? What files? The computer doesn't recognize the filesystem (hence the "1.1 GB Unknown"). It can't read and display to me which files are supposedly on the CD.

[KynloStephen66515]

Have you tried to copy the files over via CLI?  If so, what happens?

-Stephen66515 (June 07, 2017, 10:43 PM)

How? What files? The computer doesn't recognize the filesystem (hence the "1.1 GB Unknown"). It can't read and display to me which files are supposedly on the CD.

-Deozaan (June 07, 2017, 10:54 PM)

sj1k said "Get on IRC" so he can help xD

[Deozaan]

OK, we've made some progress.

I had originally booted into a Linux Live CD because I didn't know what was on the CD and wanted to make sure it didn't give me any viruses. And also because in my experience, Linux will often show you useful information when Windows refuses to. So I popped the CD into my Windows PC after failing to make any progress on Linux, and it opened right up!

It shows three images and one PDF. I was able to copy the PDF and two of the images, but the CD seems to get stuck about 50% through with copying the final image.

Windows shows that the contents of the CD take up about 72MB and the filesystem of the CD is UDF. Which all sounds very standard to me.

But I'm having a lot of trouble getting that final image to copy off the CD.

[Deozaan]

Tried using robocopy and xcopy on the final image but got CRC errors.

But here's another mystery that makes me question whether or not that "final" image is actually the final image:

The 3 images I see show as being about 9-11MB each. The PDF shows as being <1MB. That should be about 30MB total. 40MB being very generous. So why does Windows tell me the CD used up 72MB? Is it possible there are other photos on the CD that aren't being shown to me?

RESOLVED: Please help me figure out this CD

[Ath]

So... how can a 700 MB CD have a 1.1 GB partition on it?

-Deozaan (June 07, 2017, 10:38 PM)

If it's a compressed volume, backup or encrypted container. You'll have to ask the original source how the disc was created.

[Deozaan]

Thanks for the suggestion, Ath.

After trying to figure it out a bit more and getting those CRC errors, I've decided that the CD itself (or just that final image) is corrupted, and I've told the owner to try to get a new, working copy from the original source.

I'm no longer trying to figure out the problem, and no further troubleshooting is required. Thanks to everyone who helped, especially those in IRC who really pitched in with ideas and potential solutions.

[Shades]

As this topic is tagged as resolved, but isn't closed just yet, here is my contribution for those that need searchable results in the future:

There is quite a lot of software still available that helps you with retrieval of data from damaged CD's, DVDs and BluRay disks.

• IsoBuster  - Their freeware version is one I have used often myself and was very helpful to me, especially after I got a DVD burner from the Netherlands here. Much better device than any of the brands you can get here in Paraguay.
• Roadkil’s Unstoppable Copier  - this one I am familiar with, and would come in handy for retrieval jobs that I could run overnight.
• CD Recovery Toolbox  - Result of a Google search.
• IsoPuzzle  - Result of a Google search.
• CDCheck  - Result of a Google search.
• Dead Disk Doctor  - Result of a Google search.
• Recover Disc  - Result of a Google search.
• Force Copy Beta  - Result of a Google search.
• Copy Cat 3.0  - Result of a Google search.
• AnyReader  - Result of a Google search.
• CD Roller  - Result of a Google search.

Most of these are shareware tools and allow use of a subset from their features after their trail-period ends. But there are some (linked to) freeware items as well.