Computer newbies forum: My Computer will not read the disc in the DVD drive

I have a brand new computer assembled by my son. It contains a Lite-on super allwrite DVD writer, and Windows 7 operating system. The DVD writer worked fine for my son to load software. He returned to school and I can't get the DVD to autoplay or even recognize the disk.

When I started up the computer te first itme, I inserted a game disc which read fine, I played half an hour and removed it. I inserted anoter, non-game disk, same session and the disk would not work nor would the "drawar" open. I had to manually open the player and remove the disk. I powered down and checked the connections then restarted. It still would not recognize the disk. I powered down and replaced one sada cable with the one that came with the reader. It willnot autoplay, and doesn't recognize that a disk is placed in the device, but now when I doubleclick on the devicein My computer, the "drawar opens and it asks politely for me to insert a disk.
I have tried Windows auto fix with no apparent changes or results.
Any thoughts?