If you start an unattented install from a MS-DOS prompt and you receive:

Setup was unable to copy the following file, cdrom.sys.

              OR

you are unable to do anything with a file named cdrom.sys

              THEN

you probably have the ATAPI Real Mode CD-ROM driver loaded in Config.sys.

Edit Config.sys and make sure that the /D: switch in any Device= line does NOT contain /d:cdrom.