Help! Computer doesn't find CD-ROM

[Canyarion]

The CD burner of my girlfriend's PC doesn't work anymore. It used to work, but now it's like it's not there.

I took open the computer, but all the cables are connected.

I wonder if it's a software issue.
If a device breaks down, can it just disappear from your computer settings?? Sound very improbable to me.

I tried to add hardware, but doesn't find anything.

What can I do?
Thanks!