I don't use one myself but my 48 year old daughter has one she loves. It's the 2GB model and she seems real happy with all aspects of it. Of course, to get the maximum number of songs they advertise the music has to be reduced to a 64Kbs file. I don't know how that affects the quality, but with the ear buds provided I doubt you could tell much difference. The provided software is easily installed and easy to use. It allows you to rip and convert your CD's and transfer them to the Zen without much effort. For the money I doubt you would be dissapointed.

Here's an explanation lifted from a webpage: A codec is software that is used to compress or decompress a digital media file, such as a song or video. Content creators use codecs because a compressed file takes up less storage space on your computer and can be transferred across the Internet more quickly and smoothly. When you play a digital media file, Windows Media Player uses a codec to decompress the file. Codecs are used to create and play nearly all music or video files on your computer or on Web sites. Q.Why do I get a message that says my computer is missing a codec? A.You are probably trying to play a file that uses a codec that is not on your computer. When you try to play a file that uses a codec that is not on your computer, the Player tries to download the codec from a Microsoft server. If the codec is available, the Player installs it on your computer and then plays the file. If the codec is not available on the server (for example, because the codec wasn't created by Microsoft), the Player displays a message that your computer is missing a codec. If you are connected to the Internet, the message usually has a Web Help button that you can click for more information. If the Player can determine which codec you are missing, when you click that button, a Help topic is displayed that contains a link to WMPlugins.com, a Web site that lists a number of codecs that are available to download. The MPEG-2 and DivX video codecs and the ACELP.net and Ogg Vorbis audio codecs are examples of codecs that are not included in the operating system or the Player by default. Q.How do I find a codec? A.When trying to find the right codec for a particular file, you can use WMPlugins.com or other Web sites. Typically, you should start with WMPlugins.com first. Recommend that you use caution when installing codecs that aren't listed on WMPlugins.com or Microsoft.com. If your computer is running Microsoft Windows Millennium Edition or Windows XP, we recommend that you set a system restore point before installing any digital media components. This enables you to return to your original system configuration, if necessary. If you get a message that you're missing a codec when you try to play a file, click the Web Help button on the message. In the Help topic that is displayed, click the link to WMPlugins.com. If you know the name of the codec you want to find, you can go directly to WMPlugins.com Codec. If the codec is listed on WMPlugins.com, follow the instructions on the page to download and install the codec. Q.Does the Player always try to download codecs automatically? A.It depends on several factors. To ensure the Player can try to download codecs automatically, you must have Internet Explorer 3.02 or later installed on your computer, maintain Internet access while playing the file, and your Internet security should be set to Medium. In addition, if your computer is running Microsoft Windows NT, Windows 2000, Windows XP Professional, or Windows Server 2003, you must be logged on as an administrator or as a member of the Administrators group. Finally, do the following: On the Tools menu, click Options. On the Player tab, select the Download codecs automatically check box. If you use the Player in a work environment that is managed by a network administrator, you might be restricted from downloading and installing software from the Web.

It's not on a site. The video was taken with the computerized microscope named Digital Blue. (It's a "toy" scope for kids but big kids like to play, too.) The files played on the original computer when I used the Digital Blue software. I exported the files from the Digital Blue folder then, once exported, copied to my thunb drive so that I could transfer to my computer. As I said, they won't play on my computers (both Vista) even though they both play avi files from other sources. I also tried to convert to another format via zamzar but received error message unable to convert. (Sorry, I don't recall precise wording. Could try again if it's important.)

Excuse me for not saying thank you for your input above, rude! Sorry, I appreciate it. Yes, it's quite the mystery, one not answered in hundreds of articles and blogs of desperate people trying to make this thing stop. Consuming so much of their time, by the time they finally accomplished this goal, totally distracted from figuring out what the freak it was doing. I didn't forget, so if anyone offers an answer even years from now if this question is still sitting here, I will love to know. The more I learned about what this thing does, trying to get control of its' actions, the more of a mystery it became. I even deleted all of the music files at one point to see if that would do it. Nope, still sharing something. Tried looking up files by last accessed to see what was being shared but couldn't find what I wanted to know in Win explorer. I'm not much of a tweaker, just a user, more and more confused by each passing version of Windows... which always seems more and more determined to completely change everything we know how to do every time. I felt like Roy Scheider at the end of Jaws when I finally rebooted and it was stopped! Once I get back to shore on my scuba tank raft, it will be weeks before the habit of starting every fresh computer session and wake-up from sleep mode with crtl+alt+del to kill all instances of that in the task manager. I'm still not convinced I won't find it running again one of these times. There were subsequent Jaws movies, (quality notwithstanding.)