Should work fine.
I wouldn't worry about driveletter's. just boot the floppy and type A:/setup
this nornmally works
otherwise try some different letters
TheMajorMMX - Intel P200 MMX @ 225Mhz - V-Tech (PcPartner) Baby-AT mb w/ Intel Triton TX chipset - Nvidia Riva TNT2 M64 w/ 16MB - 256MB M-Tec SDRAM - Still running.....