DVDs Not Mounting On Desktop

[Paul Chong]

With all this recent going on, now I find that my DVDs are not mounting 
at all on the desktop
and hence I am not able to play them like I used to.
The Max Help section does not not seem to be of assistance.
Your expert practical advice please.
Paul
PS: Just in case, you don't know or remember, I'm using an iMac:
        Version 10.3.9          Processor 800 MHz Power PC G4
        Memory 256 MB SDRAM