it don't work man

it say this
DVRFlash v2.6.0: Pioneer DVR firmware flasher
by Agent Smith, et al., July 2008
Commandline:
C:\Documents and Settings\StaVAraSH\Desktop\yk\DVRFlash.ex
Device parameter was not given, detecting all DVR drives:
Device : F:
Vendor : ASUS
Model : DRW-1608P2S
Revision : 1.41
Status : RPC-2 (region locked)
Region : 2
Changes : 4 region changes remaining
4 vendor resets remaining
state is 'Region set'
Now run DVRFlash again, from the command prompt, using
one of the device(s) listed above as first parameter
Press the Return key to exit
then i run comand prompt and it says
Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.
C:\Documents and Settings\StaVAraSH>F:
The device is not ready.
C:\Documents and Settings\StaVAraSH>-ff F:RA143010.141 RA143110.141
'-ff' is not recognized as an internal or external command,
operable program or batch file.
C:\Documents and Settings\StaVAraSH>F: RA143010.141 RA143110.141
The device is not ready.
C:\Documents and Settings\StaVAraSH>