Well, then, we have a little conundrum. You see, there's no CD-ROM driver loaded in your config.sys file, and yet you stated that you were able to access the CD-ROM drive in DOS. However, your problem is completely consistent with not being able to access the CD-ROM drive, so I'll assume you were talking about a DOS box in Windows or something.
To get the CD-ROM drive working, you need both a driver in config.sys and MSCDEX.EXE loaded in autoexec.bat (or, if you're going to DOS through the shutdown screen, dosstart.bat). To find the correct driver to put in your boot disk's config.sys, check out the config.sys on your hard drive. Look for a line that looks like this:
DEVICEHIGH=C:\xxxxxxx\xxxxxx.SYS /D:ACERCD00
...and copy it to the config.sys file on your boot disk.