Can't see recorder/dvd drive or eject

[Macstal]

When I go into Itunes, I cannot eject drive.
When I look at Toast settings, it says that there's no recorder.
When I press eject on the keyboard, it doesn't.

But when I press alt, command ... I and O (on restart) it opens.

If I need to reinstall the DVD driver, how do I do this please?
(Because I inherited this Mac from my previous company;
and don't have any software cds).

Any ideas?

It's a Dual 2.5GHz Power Mac G5,running Mac OSX
(v.10.4.10).PIONEER DVD-RW DVR-117D.

 

[MisterMe]

Owing to your source for this computer, it almost sounds as though the optical drive was disabled. This is something that I have seen in the PC world, but never with Macs. Under normal I don't recommend reinstalling the OS, but I do so in this circumstance.

 

[Macstal]

This means I'll have to reinstalling my software also, doesn't it?