Write protection on a DVD is used to keep its contents from being erased. If you have a DVD that you want to copy (or write) over, you won't be able to do so until the write protection has been disabled. The only way to disable write protection is to format the DVD; do this through the Windows 7 operating system.
Open the optical drive on your computer and put the DVD into the DVD tray. Close the drive and allow the computer to bring the DVD onto the screen.
Click on the "Burn Files to Disc" option in the right-hand side of the screen. Type the name that you want to associate with the DVD into the box that appears. Click the "Show Formatting Options" icon.
Click on the "Live File System" option from the menu. Drag the files that you want to copy to the DVD, to the window.
Click on the "Mastered" icon to have the files copied to the DVD. Click the "Next" button to prepare the DVD.
Click the "Burn Disc" option to write over the original files.