If you don't already have it, try adding:-
LASTDRIVE=Z
in the CONFIG.SYS file.
Did you carefully watch your screen as Ed Fair suggested? This will give you vital info on what is happening when the drivers are loaded. A failure will produce an error message.
The POST screen usually lists all main devices found. Does it show hard disk, CD-ROM, as well as the floppy, etc etc?
ROGER - G0AOZ.