I am on a Dell Inspiron 1100 and when I boot the system, most of the time, I get an error before the BIOS loads that reads as follows:

"The Device in the system modular bay cannot be identified. It may not be completely inserted or may have some other problem. Please read and complete the following steps.

1. Press the device completely and firmly into the bay.
2. Press the ESC-key -- wait for the system to power down.
3. Press the power button to retry detecting the device."

My BIOS version was just recently updated as I ran into the problem to BIOS Revision A32. I called Dell Technical Support and the support told me to remove the optical drive and reinsert it. I did as told. I booted the system up and before the BIOS loads, bam, error once again. The technical support didn't even know what to do. The support said that I may have a failing mobo. Now, how would one go about seeing if their mobo was failing? I'd really love to check this before actually going to purchase another mobo, Hell, purchasing a brand new computer or building my own considering I am sick of Dell's erroneous electronics.

You should first try a second hard drive with a full install. That usually fixes the problems with the 1100, 1150, 5100m, 5150, and 5160 which all seem to have the same problems.
Remember that this optical drive is fragile, and has a history of failure. New models are available with DVD RW that are quite reliable, on eBay. They range from $72 to $85 to $89 to $95. If you are good with tools, you can get the generic one, then revise the hardware to make everything fit just fine.

Having the same problem with a c840. Nothing to change setting in bios. I have A: drive in that works fine, but when I try to insert CD Rom I receive the same error. I can let it boot with out a drive, then insert the CD Rom into that bay and system will reconize it. I wanted to reinstall winxp so that is not good enough to try.

The Device in the system modular bay cannot be identified. error fixed

I just dropped my friend's laptop Dell Inspiron 8600 ,and broked its DVD/RW drive.After replacing it with a new DVD/RW bought from the store,other brand and model than that i've broked.
"The Device in the system modular bay cannot be identified." appeared.

Had to buy and install the same part model of DVD /RW with the original.
It works again. No error again. Bye