Windows 7: CD reads but wont play - disappears

Dell 755 dual core 1.8, 3 gig ram.
I installed Window 7 on the machine, updated the drivers for sound ect.
The problems is the CD drive, it can see it read what’s on the disk, when you try to open it, it disappears completely off the machine, it goes out of devise manager, reboot it comes back.
If i try to play a music CD it loads the WMP and tries to play you can see it playing, the track bar moves but no sound comes.
If I play the in-build music or play the video it plays and I hear the music.
I've changed the drive letter as someone suggested still the same.
At one point I had my 3g modem in that show up as the CD drive.
It must a conflict somewhere, where I don’t know.
Set it to both 32 & 64 bit configurations it’s the same on both

Some 3G modems start as a flash drive and a virtual CDROM drive is created switching it to a modem. This can indeed create conflicts with the physical drive. Yep, a drive letter conflict.

You have a DELL machine. How did you reinstall Windows? From the DELL Reinstall DVD or the recovery CDs? ( I know DELL sends the Reinstall DVD - not the recovery CDs - on request.)

At what point did you connect and install the the 3G modem? After the reinstall?

Now I am just shooting in the dark.

May be changing the drive letter of your physical DVDROM drive - to say Z - immediately after the reinstall and before connecting and installing your 3G modem will help.

Changing it after the conflict is created may not help.

Hi
The problem started directly after I installed Windows, I wanted to install other software this is when I noticed the problem. It's the same CD Rom that I used to install Windows 7.
I had nothing else running, no modem, no other devices, I have both a USB mouse and keyboard that's all.
the first notice I had was about my sound card, I played the in-build music and it worked OK. I swapped my HDD and used XP to download the drivers. SoundMax
The 3g modem issue is later down the line. It was in the USB when I booted up one time, I just noticed the change that's all.

I've install the Windows 7 on 2 of my other machines, Dell GX 270 & GX 620 both are working fine, I had to update the sound card.
it's not a Dell Windows 7 installation disk.
Thanks

The issue is still not very clear to me. Is your Windows 7 genuine with a valid license?

Why swap the HDD and use Windows XP to download Soundmax drivers for Windows 7 ?????

Anyway now that you must be having all the necessary drivers, I can only suggest that you wipe the HDD clean, reinstall Windows 7 making sure that you have no other USB device connected during the installation (except KB and mouse). Change the CDROM drive letter to X/Y/Z , then do whatever else you want to do like installing drivers, installing the 3G modem etc and check whether it resolves your problem.

Yes, I have a valid license windows 7.

The reason I changed back to my XP, simple this, I'm not to conversant with Win 7, my modem and bookmarks are on there, I have internet security, don't like browsing without AV ect, I use IDM when I down load ect ect. any file I down load I can scan, I wasn't installing my AV on this machine until it all worked. I live in Africa we have many problems with power and ISP connections.

I will reinstall it again, I did install the first time as 32 bit, then i reformatted and install 64 bit still the same.

Thanks

I think you are too much worried about connecting to the internet.

During Windows 7 installation there is no need to connect to the internet.

In the screen you enter the product key, uncheck "Connect automatically" and complete the installation. You have thirty days time to activate and can do that after you are satisfied that everything is OK with the installation.

You can download Microsoft Security Essentials from another computer and keep it ready. Install it immediately after completing the clean install. Change the drive letter of your DVDROM drive to X/Y/Z before connecting the 3G Modem. ( I am assuming that as a USB device, it installs from within itself, with no requirement on you to install any driver. If it does require a driver to be installed then download it from another computer as well.)

With connection to the internet with MSE already installed you are safe to download any drivers from the manufacturer's/software author's website.