^^

so, you installed winflasher right?
Now you need to copy the firmware.bin file to where the flasher.exe is

thats usually under C:\Program Files\Nokia\Flasher

now you need a CMD promt with admin permissions!

press start and type cmd in the search bar -> right click on cmd.exe and run as administrator

then navigate to the flasher folder (where the flasher.exe and your firmware image are)

to do that type in cmd

EDIT

to make things simpler rename the firmware image to main.bin

now you are ready to flash your device

shut down your N9 (if it's not already off) and

type this to flash the firmware

NOW you need to connect your n9 via USB and it should start flashing the firmware
you can monitor progress in cmd window

if it writes something like "success" or "flashing successful"
or something

type
and disconnect usb

there it is! good luck