Thanks For helping.....My flashing is successfully been done 
But sad to sy that my all the Settings have been Changed and messages have been Deleted and applications too!!.. 
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And also can you tell...Every Time I flash same thing will happen and can I install Firmware Of N8 in my nokia C7??
Answer your first Question :-
yes every time is the same when you flash your phone in any other Firmware or CFW. U need to back-up your all msgs and Contact too... and about the application there is no way to create application back... so you loose your all apps when you flash again....
Answer your Second Question:-
No... you can't do that.. n8 firmware is a different firmware its only for n8... and you did not use any other Firmware except for your Phones firmware in your phone.
and about the N8 firmware there is so many CFW available just like n8 firmware for the C7 users.
you can use that on your phone.
but every time before the flashing ...... just make your phones back-up first.
how to create back-up just open File manger then choose restore and backup option the click on back-up, in this option u have to option for select your personal back-ups which is you want to save in your phone... just like MSGs, Contacts, phone's home screen setting, and some other things...
and you can also set the schedule for the back-up every day, every week, every month or specific time.
its a awesome feature in belle... or previous Symbian^3 device too...
