Venue Pro 7139 fingerprint scanner not working

My 7139 venue pro fingerprint scanner does not work. i have tried uninstalling and re-installing drivers.

it finds it in device manager but when i go to add fingerprints its greyed out.... i have tried sfc/ scanonly in cmd. sometimes it comes back i can click add fingerprint but it then it still then it still doesnt add any and greys out again......

I was going to erase windows and restart everything but it comes up with an error- insert media some files are missing.....

any help would be appreciated.

thanks