First of all I am pretty new to this so I hope I am posting the right information. For some reason I can't get the avi files with the Xvid codec that I burned to a CD to run from the disc. Files with other, earlier codecs work alright from disc just not Xvid files. But the exact same file that is stored on my hard drive will work. The error message that I get from WMP is "Classfactory cannot supply requested class" and when I try Zoomplayer I get a message stating that it cant find the necessary filters or its a corrupt file. I have tried deleting and reinstalling all my codecs as well as deleting and einstalling Nero then doing another test burn to see if that would fix the problem. Still nothing. I'm guessing there's some sort of problem in the burn process but short of reformating or replacing my cd burner, I don't know what to do. None of my searches have amounted to anything except that I have seen a few messages on other forum boards having similar problems but with no responses as of yet. Has anyone been able to solve this problem? Any help or suggestions would be greatly appreciated. I have installed the latest codecs using the ACE Mega CoDecs Pack along with the most recent Xvid installer that I could find. Nero 220.127.116.11 SAMSUNG CDRW/DVD-ROM SM-3088 WinXP P4 1.8 256 MG 133 Ram have I left anything else out?