Back-Rev Firmware

For testing purposes I would like to “back-rev” the firmware that is on my Acceleport 4 card. Currently I am using firmware version V80006691_M3P_K56_DS, but I would like to re-flash the firmware to a prior version.

When I put a prior version of fepdense.bin in the windows directory \system32\drivers and restart the computer, the firmware version doesn’t change.

Is it possible to back-rev the firmware?