CD-ROMs are very resilient and sturdy. Unless there is a major crack on your 
CD-ROM it is not defective. If it was, you would not be able to read anything 
at all from the CD-ROM. Nowadays, we all have big hard drives, so space 
limitation should not be an issue. 

SOLUTION:
    Please try copying the contents of the CD-ROM (root and Installation 
    directories) to a directory on your hard disk. (you can delete them later)
    Then execute the Setup program from the hard disk instead of your CD-ROM
    Drive. If the Setup runs (from your Hard Drive) you may be certain that 
    your CD-ROM is fully functional but there may be an issue with the CD-ROM
    Drive instead, that you may wish to address. 

IN DETAIL:
    -  Insert the VTB CD in your CD or DVD drive.
    -  Open Windows Explorer (Start > Run, type in Explorer and click OK). 
    -  Open the My Computer tree and navigate to the location of the CD 
       or DVD drive. 
    -  Copy the contents of the CD to a folder on your computer's hard drive.
       (Right-click on your drive and choose Copy from the menu. Right-click 
       on your Desktop and choose Paste from the menu. The contents of the VTB
       CD should copy to a folder on your Desktop.)
    -  Close Windows Explorer and return to your Desktop. You will see the 
       new folder. Double-click on it to open it. 
    -  Click on the file SETUP.EXE (may show as SETUP) to launch the
       installer.
       Follow the onscreen prompts. 
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