檔案解壓縮後..
解在 c:\ 下面
進入XP等DOS模式下(命令提示字元)
到 c:\ 下打 necbfl
會出現如下畫面
NEC ND-35xx & 45xx bootcode flasher 1.0 * 2006 [Wb']
credits goes to authors of PLSCSI and Trace SPTI tools

PLSCSI.EXE program found.This power tool came from:
http://members.aol.com/plscsi

SCSI devices listing此動作先檢查您的硬碟跟光碟機的配置圖)
set PLSCSI=\\.\C: // @ 硬碟一 maybe
set PLSCSI=\\.\D: // @ _NEC DVD_RW ND-3550A 1-05

Enter your drive letter or LUN (e.g. "\\.\X:","3.0.0") from list above:
在這地方鍵入(您光碟機所在地 ) \\.\D:

然後會出現
Your drive ID is: K450 - ND-3550A
Make sure this match with your real drive model.
If you previously tried to change drive ID with NEC
Drive Converter tool press
CTRL-C now and change it back!

Now you can choose your drive target model:

1) ND-3550A
2) ND-4550A
3) ND-4551A
Enter [1/2/3]:
你就可以選擇您想要的機種,可以鍵入2或3(如果我們選3會出現以下畫面)

New drive ID will be: K451

You have last chance to abort before flashing the
drive, continue? [Y/N]:
問你是不是要升級,然後鍵入Y
就會開始動作,一直等到動作全數完成...
NEC的機器會變成燈一直閃，要先重開機後,用LIGGY的任一款破解非官版4551的韌體,再升級一次,再重開機一次就算完成..
完成後就可以燒NEC 4551該有的功能了..