Those who have my MSN already saw my nick...
For those who doesn't have my MSN...
DivoCodec is a codec that is bundled with adware. If you install it... you will install some adware crap. You will notice popups from CiD.
For the curious, part of the EULA says this:
3) By accepting this agreement you acknowledge that in order for this software to function properly it must communicate with its host network via the Internet from your computer. You hereby grant your explicit approval for this software to communicate from this computer system through your software firewall or hardware routing system (if present) with CiDs' host network. For users of Windows XP Sp2 this softwares host domain names will be added to your web browsers allowed list for popups. Because this software will incorporate as part of your Internet Explorer web browser package and will run as part of that process when active on your system, your firewall or router may not prompt you for communication access once this software is installed.
Now you know where your CiD popups are from.
Google it and you know where to download this codec.