Houndog777

Hi,
If it's listing cd/dvd rom on start-up then it should be ok.
In older bios you will have a list of your drives, some give you details of cd under the hard drive info of size, heads, cylinders etc., which you can highlight then press Enter to auto-detect if a cd drive is indeed installed.

What is the full title of the ThinkCentre? I just went to look for a manual and discovered there are many different types.
Example: Family-Thinkcentre M50 Type-8187 Model-34T

You say you entered temporary boot config to set order; try entering bios proper and setting the boot sequence to cd rom first, save and exit.