As I understand it you have 3 devices. 2 internal, and one external DVD that won't install completely via USB.
I am inclined to believe the following.
Both internal devices may have failed as the IDE socket they share has failed. You can verify this by opening the case and confirm that they are both on the same cable.
If they are, I would transfer one device over to the still functioning other IDE cable/channel and see if the device works on another cable/channel.
If it does, you will then need to determine if the IDE socket itself (on the motherboard) or the cable that's plugged into it is bad. Obviously, we are hoping for the latter.
I do not think your USB/external DVD device is related to this other problem, nor do I believe that both your internal CD-ROM and DVD devices failed simulateously.
Try to do the above troubleshooting method. Also, return to Device Manager and make sure to enable "show hidden devices" and report any other yellow or red flagged devices you may have besides the USB DVD device.