Can boot with Win7 DVD but once logged into Win7 CD doesn't work

I have an HP laptop nc6400 running Windows 7 SP1. I am having problems with the CD player - it doesn't recognize any CDs I put in! When I try to put in a CD, it ejects the drive and comes up with the message "Please insert a disk".

I have a Win7 SP1 (burned) disk. When I put in this disk, and boot from CD drive, it launches the Windows 7 install program. I select the "repair" option, and repair startup files. It completes without errors. (This is the same disk that wasn't recognized once in Win7).

Someone recently replaced the CD player with a different one - both players had the same problem (it is now a HL-DT-ST RW/DVD GCC-4247N ATA Device). I've tried updating the driver (in Device Manager) and even uninstalled it and had it re-discovered and installed.

When I run SFC /SCANNOW from the boot DOS prompt, it says "No errors".

When I log into Win7 and run SFC /SCANNOW from an elevated command prompt it says there were files that were corrupted but unable to fix. I created the SFCDETAILS file, but searching for "fail", "corrupt" and "unable" yields 0 results, so I don't know what files are corrupt.

I'm not a hardware person, and this is a work computer, so I have limited ability to do anything hardware-wise. But considering the DVD player works to boot from, but doesn't work once logged into Windows, I'm thinking it's a software problem (but don't know what the problem is).

Any suggestions would be greatly appreciated!

Hmmm... no comments... I think I posted a doozie!

As an update - I was able to successfully burn a CD on the drive. I located an ISO file and burned it to a CD-R. I heard the 'whirring' for a few minutes, it said it was done and ejected the drive. I looked at the CD and it appears to be written to. I look at the drive in Windows Explorer, and it shows D: is a CD-R with 360MB free of 702MB. Hurray! However, when I double click D to open it, it shows "Files Ready to Be Written to the Disk" - Desktop.ini, and no other files. I can't run D:\setup.exe (windows can't find d:\setup.exe). So something is not right...

I put my Microsoft Keyboard/Mouse CD in the drive, and Windows Explorer doesn't recogonize it (Please insert a disk).

I ran Microsoft Fixit for playing CDs, and it said it couldn't find any errors.

Does this illuminate the problem any further?

I've had another 'ah-ha' moment... From Windows Media Player, I burned some music to the CD. Within Media Player, it shows the songs on the CD and will play them. Hurray! Through Windows Explorer, it doesn't recogonize the disk is in the drive (Please insert a disk). So it's just Windows Explorer that's messed up (the CD drive is working!).

Curiouser and curiouser...