"Device in system modular bay cannot be identified"

This happened before, about a year ago, back when I still had Dell Support software on my PC.  I used the Dell support software to fix the problem, and it worked.  Later, I uninstalled the Dell Support software because it was giving me headaches.

So, now, I'm having this problem again.  My system does not recognize my CD/DVD player on start up, and so I can neither open the CD/DVD player by pushing the button, nor play a CD or DVD when I use the point of an opened paper clip end to poke into the hole to open it.

I know it's fixable with the Dell Support software I used to have, but I dunno how to fix it now.  And I really, really need to use my CD drive to install some software.

Can anybody help me with this error? I've got a Dell "Inspirion 1521" laptop, and Windows Vista operating system.

Thanks.