By Lou Dolinar
Updated Feb. 14, 2006

Recordable CDs are supposed to last a lifetime, but many users find them failing in weeks or months.

Last week, we looked at why, and how you can prevent it - for the most part, by using manufacturer-recommended media and careful handling.

This week, we'll tackle another issue: How do you get back data from a damaged CD? The first option is specialized software, because normal hard-drive recovery tools won't work.

I took a look at three programs designed to retrieve lost information from CDs and DVDs you've recorded: IsoBuster (www.smart-projects.net; $25.95); CDRoller (www.cdroller.com, $29.50) and BadCopy Pro (www.jufsoft.com, $39.50).

All are produced by relatively small companies and aren't particularly simple to understand and use. While my tests were fairly limited, the good news is that you can download trial versions of all three programs free, then try to view your data. Assuming you can see it, it's safe to go ahead and buy the program to retrieve it.

How do these programs work? To grossly oversimplify, according to Bob Smith, an application engineer with Plextor, these programs attack the directory structure of CDs in nonstandard ways. There's a lot of redundancy on CD-Rs, and it helps that CD-R writers lay down tracks of data sequentially, from the beginning to the end of the disc, unlike hard drives, which scatter individual files at random wherever space is available. Also unlike hard drives, rewritten information is always there, intact, in its previous versions.

To test the programs, I created some fake "damaged" CD-Rs. First, I simulated what would normally happen if you were, for example, backing up a word processing document over a couple of days. Unlike a hard drive, every time you save a copy of that document to disc, a new version of it is created on the CD. Because a CD-R isn't erasable, the earliest version and all interim ones are still there intact, though not visible to a standard Windows directory. Assuming you've somehow trashed your final version, wouldn't it be nice to get a previous one back?

Then I tried to simulate what happens when you fail to properly close a CD recording session in Windows XP. I created a folder on my hard drive and put about 20 MP3 files in it. Then I dragged the folder to the CD and began writing it to disc. About halfway through, I turned off the computer.

I physically damaged my third disc - turned it over and on the shiny side scribbled with a ballpoint pen.

In my first test, IsoBuster retrieved all versions of my backed-up word processing document quickly and simply, and didn't require me to tinker with any settings. It failed to find the MP3 files in test 2, no matter what settings I chose. And the physically damaged file was unreadable.

BadCopy Pro fared better, though it has a stunningly inept user interface. It runs in a minimized window centered on the screen. Unless you enlarge the window, some of the controls are invisible, including the one that lets you choose from three ways of extracting data from the disc. I struck out totally until I discovered this setting, which allowed BadCopy Pro to grab both the word processing documents and the MP3 files. Still no luck with the physically damaged disc, however.

CDRoller wouldn't read any of the discs.

Still, I'm not going to knock any of these programs. The experts I've talked with emphasize that there are lots of ways in which CD and DVD writing can be messed up and that these recovery programs don't represent a mature technology as yet. So I'll stress what I said the first time: Try them out. And you may have to spend a fair amount of time messing with settings to get results.

What's your next step if software fails? No guarantees here, but physical restoration may help. If you're having problems with lots of discs, you could try cleaning the lens of your CD-R drive according to its manufacturer's specs, which you'll find on its Web site. Plextor, for example, suggests blowing out the drive with canned air but does not recommend cleaning kits that use special discs to buff the laser lens. Such cleaning, they say, can scratch the lens. I've used the kit sold by Radio Shack togood effect, but maybe that's just me.

If the disc is scratched or scuffed, you also can try to physically repair it by buffing out the surface imperfections. Here, you run the risk of inflicting further damage - not a problem if you've written off the disc anyway, but these procedures may preclude help from a professional recovery service. The best reviews I've seen of repair products are at www.burningissues.net, which compares four major kits to various home-brew remedies. The conclusion: Brasso, a metal cleaning paste, is the most effective buffer. Just remember - unless you've removed all the crud from one of these operations, you run the risk of damaging your laser.

Finally, for truly critical recovery, you might consider a data recovery firm. Fees are all over the place here, from as little as $50 per disc to more than $500. Most claim to have proprietary hardware-based systems for recovery operations, so you might want to do some research before you make a decision.