Check which error DOS is reporting: 

1) Exit Windows

2) From DOS type "DIR D:" (if D: is the CD-ROM drive)

3) DOS will display one of the following errors:

   a) "CDR-101: Not Ready Reading Drive D: Abort, Retry, Fail?" 

      This means that the drive is timing out when trying to read from 
      the table of contents.  This can happen on Multisession rewritable 
      discs that have a large number of sessions on them.  This also 
      happens when attempting to read an audio disc. 

   b) "CDR-103: Non-High Sierra or ISO-9660 Compatible..."

      This error usually occurs if the CD-ROM is connected via a sound 
      card, and the "JP1" or "IDE JP" jumper that selects either the AT 
      or IDE interface is set incorrectly. 

      If that jumper is set correctly for the interface being used, then 
      the disc that is in the drive is unreadable; a likely scenario is 
      that the CD is a Macintosh-only disc.