Why isn't the Windows Hello option showing on my HP Elitebook 8440p?

[Windows Central Question]

window hello option is not showing on hp elitebook 8440p

i upgraded my hp elitebook 8440p to window 10 pro from window 7. as my elitebookss consists of fingerprint sensor but i am unable to use it. in sign in setting window hello option is not coming, and one more thing i am having preinstalled validity fingerprint sensor but i have never used it. plz any one help me out from this problem.