I know ive ask this before?

Codecs are the bits of program which interpret the file correctly. First you need to check your dvd writer doentation to see if it support the disks you are using. Second, it will need codecs added to whatever player program, but the burner should be able to supply its' own method to convert the film. If it is copyrighted there is protection against infringing the copyright built into the disk.I hope you did not just delete anything from Nero, you must NEVER do this to a program, you need to uninstall it. Deleting it only takes away the part you delete, it leaves a lot of the program on the machine and can make the machine unstable. It also means the uninstaller can no longer remove it correctly. Take a look for cdburnerxp (Google search for this).