As I have seen, most people posting here have this problem. So lets start off with the problem. When I try to go to "Create a DVD with MyDVD ®" I get this error message: "The following codec(s) must be activated before using the application: MPEG-2 / Click OK to activate or Cancel to abort.

I click on OK and another message comes up: No permission - Bad installation

As I have read around the forum, I see that the answer to this problem is uninstalling Roxio. Do I just uninstall Roxio, or Sonic also? And to reinstall both, I have Roxio Creat & MyDVD 9.0 DE and Sonic CinePlayer Software CD's. Would those CD's reinstall the software that I would uninstall?

You want to follow this information to the letter removing everything Roxio/Sonic.
Or, if running Vista, use this one.

Thanks. Hopefully I won't mess up.

Should I do Add or Remove Programs, or the Windows Installer Clean Up Utility?

I've found the MS Cleanup utility a bit better but just be sure after you use it and follow the instructions that all the Roxio folders are deleted. Unfortunately, there were sometimes that I had to follow this procedure more than once so please be patient.