Disc drive

Hello,

Lately, I've been noticing my disc drive hasn't been working right.

Yesterday, I inserted a blank CD to burn some songs onto. It detected the CD and began to burn. An hour later, when I went to rip the songs from the CD so I could use it in a different program, my computer kept telling me to insert a CD. I figured it was a temporary thing so I shut my computer down.
Today when I checked to see if it was working by using a different disc, it worked. When I put in the one I wanted to use, it again told me to insert a disc. I checked my computer to see if the CD would show up there, but it also told me there was no disc inserted.

Can anyone help me get my computer to detect the discs?

Also, I have a compaq. I'm not really techy or anything, so I'm not sure of the model.