This may be a DNS issue - maybe not.
I had a user who was encountering some printing problems yesterday. I got the printing problem solved but in doing so discovered that I was able to ping the PC using two different hostnames, but having only one IP address. I've verified that the inaccurate hostname belonged to a workstation I've already removed from the network 30-45 days ago.
On a side note, I've since upgraded the OS from WIN 7 to WIN 10.
Now, 24 hours later, I'm still able to ping the one workstation by the two different hostnames. Is there something else I need to take a look at? We do have some special vlans that live in our enviornment. Is it possible that, maybe, the MAC of the PC got assigned on a vlan and is somehow associated to the old PC name - or is that really thin possibility? Just tossing ideas around.