If you have a CD or DVD burned in the UDF format, you can add, delete or modify any data on it provided that it has sufficient free space. CDs and DVDs burned in the ISO 9660 format, known as Mastered or CDFS discs, do not allow you to add, delete or modify any data once they have been burned. The built-in disc-burning tool in Windows 7 allows you to burn data in the UDF and ISO 9660 formats, so you can convert the data on a UDF disc by copying its contents to the hard drive and then burning them to a new disc using the ISO 9660 format.
1. Insert the UDF disc and open Windows Explorer by clicking “Start” and “Computer.” Right-click the CD/DVD drive icon and select “Copy.” Next, right-click a vacant area on the desktop and select “Paste.” Your computer will now copy the contents of the UDF disc into a new folder.
2. Insert a blank disc into your computer’s disc burner. Click the “Burn Files to Disc” option on the popup window.
3. Enter a name into the box next to “Disc Title.” Next, specify that you want to burn the disc using the ISO 9660 by clicking the “With a CD/DVD Player” option.
4. Go to the folder on the desktop that contains the copied items from the UDF disc. Hold the “Ctrl” key and click on each item inside to select them. Right-click on any one of the selected items, point to “Send To” and then select your disc burner.
5. Open a new Windows Explorer window. Right-click the disc burner drive icon and select the “Burn to Disc” option. Windows Explorer will now burn the items to the disc using the ISO 9660 format.