Philips DVD eats my CPU capacity

At very irregular intervals (I suspect when I am not actually using the computer) I hear my DVD drive spin and see the mouse icon replaced by the disc icon for a moment.

 

After that, when I look at my CPU performance about 20% of its capacity is in use constantly! This means everything is jerky - so I can forget playing any sound or games!

 

I have tried updating the driver and am told that I have the most up to date one already.

 

As I rarely use the DVD player can I just go inside the case and unplug it?

 

 I have tried to disable the DVD player but when I next power up it is back there again - or my ordinary CD drive isn't. I DO use that!

 

If, after one of these 'events' I go to look at the properties the whole computer freezes. Even CTRL ALT Delete doesn't work! I have to resort to the index finger pressing the power button.

 

Any ideas? Please???