In an earlier thread I saw someone mention programs for PC that allow you to check your DVDs for errors. Could someone point me in the direction of these programs? If any freeware ones are available that would be great. Any help would be much appreciated.

what type of errors?

Universal's DVD-18's come to mind. I've never had a problem, but I believe if you run some of theirs on that program, you'll get an error or two. I'm sure it's playback related.

Nero has tools for this that can show you the bad sectors. Don't know of any free tools.

Nero CD-DVD Speed

ScanDisc
Improved user interface
Increased accuracy
C1/C2 or PI/PO information can be used to check the disc quality which gives much more detailed information than the standard read test
The quality of each track (AudioCD), chapter (DVD Video) or file (Data disc) is shown which makes it very easy to verify the integrity of the disc contents

K-Probe is nice if but only works with a Lite-On drive. Nero CD-DVD Speed should be sufficient for most people.

http://www.k-probe.com/

how do you know which release is dvd18, dvd 9, or so on?

Yes, that's how I do it. People seem to like BenQs and to a lesser degree Lite-On and NEC for use with Nero CD-DVD Speed.

eau, how do you get it to tell you which chapters/files are bad? If that option exists I must've missed it or it must only be in the latest version (but not mentioned on their web page)?

I finally opened up all my Abbott & Costello volumes and my Don Knotts Reluctant Hero pack, and after scanning them I regret that I didn't return them all unopened for store credit somewhere because more than half of them have horrible error scans right at the layer change at the edge of the disc. I tried several drives on a few of them are they are absolutely unreadable and unplayable beyond a certain point. I assume I'll have to go through the ordeal of trying to get replacements from Universal at some point, but too many other things are going on to worry about it now.

What I have learned is this. If I ever do buy a Universal DVD-18, I try to find one without a Made in Mexico sticker (my Frighteners and Blues Brothers have excellent scans and surprise surprise no Made in Mexico sticker). Now I will open and scan them within 30 days so I can return at the store.

I can tell by looking at the Nero scan if I'll have any trouble playing the disc.

1. Play your disc with a DVD software player for a few seconds.
2. Run CDDVDspeed, click on the "ScanDisc" tab.
3. Click on Start and let it do its job.
4. After the disc is scanned, look at the file and quality columns at the bottom of the window, which tells you which files pass and which ones fail the scan.

eau, which version of CDDVDSpeed does this work with? I tried these steps on 4.01, and I didn't see any file and quality columns at the bottom of the window. Either it must be only in the latest version (I didn't see any mention of it in the latest version's release notes), or there must be something else I need to do to enable it, or maybe it doesn't work for BenQ drives.

I was using version 4.10 (download). I actually scanned a DVD in order to get those steps right. The first time the scanning halted at the 90% mark and I had to stop it, but the quality column was empty. I scanned the disc again and it went all the way through, then it showed the quality in all the files/chapters as being good. I'm not sure how accurate it was. It didn't seem to show anything if it couldn't complete the scan.