Find user name with IP address

How can I find who has logged (name of the user) in a computer using IP address in LAN?

Go to a command prompt and type the below 2 commands:

nslookup ComputerName
ping ComputerName

I believe that the multiple user user which logged in can be anybody or nobody the machine that time. So i think there is no way to find which user is logged on.

If someone is logged on the Explorer.exe process. Query the remote computer using WMI for that process object. You can determine programatically determine how long that user has logged in. The defaultuser name value in the registry can be use to determine the previously logged-in user if explorer.exe is not running.

If you are in LAN and you have someone's ip address and you want to know his user name and if you use active directory (AD) then you can use the following process to find out the username:

Step1:- In the command prompt enter the following command:
nbtstat –a ipaddress("ipaddress" is the ip address.)
This will list the machine name using that ip address.

Step2:-Then run the following command:
net view /domain:ad > somefile.txt(Where ad is the name of the domain you want to search and somefile.txt is the name of the file to contain the output).This will generate a list of every machine and who is logged in.

Step3:-Open the output file and search for the machine name determined in step 1 (the username will be listed next to this).