Is there a program I can run to list all or most network Computer Names/IPs (on win7&XP) and also list the user name logged on the device.

I usually Use Computer Management > Shared Folders > Sessions but with recent traffic on the server that uses computer management I'm running into issues were it's not available to me. Wondering if there is an alternative I can run from another network computer or server to list the info I need. I know there are ways to list all active computers but I also need current logged in users listed as well.

I really could use some help on this one.