CD-ROM Issue

I have a home network with 3 computers. 1 with W2K desktop, 1 XP Home laptop and 1 XP Home desktop. All have plenty of Ghz & RAM. All antivirus def files are up to date and systems are scanned regularly. Attempted to install SIM2 however 2 of the 3 computers would not recognize the CD in the drive. On the W2K and XP Home laptop an error message said to Insert Media into the Drive. How can I get the computers to read the CD?