cd-rewritable disk; why read-only on computer?

[Explorer-8]

I have a folder (with 15 files) on a cd-rw disk. Whenever I try to re-write the folder with updated files from the hard disk using "My computer" on Windows XP, there is a window appearing on the screen saying "read-only" disk. Even when I try deleting the old folder first, my computer won't allow it because it says that it is read-only. Why is my rewritable disk appearing to be read-only instead of a rewritable?

[mr_g_uk]

Does it have any scratches or any signs of damage? I've had the same kind of problem before which rendered the disk read only. Hence, I don't use CDRW anymore, USB sticks are better for me lol

[magicmerlin]

I think you may have to re-format the dvd then you can re-write with whatever you want. I believe that you cannot add files once you have had one recording session unless you tell it not to finalise, but then you will not be able to use on another computer. They cannot be used in the same way as a memory stick. If I am wrong I apologise, I am learning all the time.