Question : Problem: CD-ROM Disable in Dell OptiPlex SX260

I've recently replaced 8 Dell OptiPlex machines with HP's, and wanting to reuse them, at other locations at the biz, my goal was to re-install the operating system.

I was successful in 3 of the PCs, but the other 4 won't recognize the Re-Install CD at all.
I've tried replacing the CD-ROM Drives, with no luck.

I'm assuming at this point the previous System Admin, disable the drives.
Is there anyway for me to tell? And if this is the case, does anyone know
how to re-enable them?

Thanks in Advance!

Answer : Problem: CD-ROM Disable in Dell OptiPlex SX260

sorry other way around disabled = 4 enabled =1