This is done by pressing the Caps shift, Space bar, Delete button and Power button while booting up.
Hard reset the N97
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ffmpeg -i YourMovie.avi -b 2300k -r 30 -s 640×360 N97movie.mp4
or
ffmpeg -i YourMovie.avi -f mp4 -acodec mp2 N97movie.mp4
follow: