Help Problem for update

[Dartanian]

The recovery.img file is on my sd card but i don khnow why comes this error.
please help me.

C:\>C:\android-sdk-windows\tools\adb.exe start-server
adb server is out of date. killing...
* daemon started successfully *
C:\>C:\android-sdk-windows\tools\adb.exe shell
# su
su
# flash_image recovery /sdcard/recovery.img
flash_image recovery /sdcard/recovery.img
failed with error: -1
error opening /sdcard/recovery.img#