Is this the same N950 as in your original posting or a different one to avoid repeating myself?
http://talk.maemo.org/showpost.php?p...58&postcount=1

Sounds as if in "boot-loop" so you might need to set in R & D mode and re-flash firmware similar to procedure upon N9:
https://talk.maemo.org/showpost.php?...50&postcount=1

Personally I would always use Windows 7 in place of Windows 10 for mobiles of this era, simply to avoid "driver signature enforcement" issues.

Are you sure that device has powered down properly before connecting to flasher, by keeping power switch depressed for at least 8 seconds?