hi

after my n900 ran outta battery, i plugged my n900 into the socket and turned it on. all the names have underscores in them and it is all screwed up
for example
the name for media player is mp_ap_name
and the one for calender is cal_ap_name

please help me fixed this problem i have tried to restore it but all the names are still screwed up

I think those are the "internal" names, which should be translated into your own language, so it sounds like the device has forgotten what language your phone should be. Try going into Settings, then Language & region, and setting the device language (top button). I realise this might be tricky!