Re: Erase DVD-R data
That is why it is a R not a RW. Meaning you physically cannot format and rewrite to an R disk. The dye on the disk will not allow it to physically be rewritten to. On a RW you will notice the color of the disk is different because the dye on the disk allows for rewriting. From Wikipedia: The recording layer in DVD+RW and DVD-RW discs is a phase change metal alloy (often GeSbTe) whose crystalline phase and amorphous phase have different reflectivity. The states can be switched depending on the power of the writing laser, so data can be written, read, erased and re-written. DVD-R and DVD+R discs use an organic dye.
Similar to what I was saying, just a bit more technical. It is the compound on the disk that allows (or does not) rewriting.
Has nothing to do with software, it is physically impossible to do what you are trying to do.