Getting logged in domain user

I know it's been asked a thousand times, and answered as many around Google, but the suggested solutions don't seem to be doing what I need.


All I'm trying to do is pull the current user's login name from Active Directory.


I've tried User.Identity.Name.ToString, which returned nothing at all.
I tried Environment.UserName.ToString, Which returned "NETWORK SERVICE" which is not the firstname.lastname username that I was expecting.
Are there any other options I can try?


Thanks a bunch

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