NetworkOpenedFiles is a tiny portable utility which lists local files that are currently opened by other users on your network.
For every file, the program displays its name, user, computer name (if you're running Windows 7 or later), read/ write/ create permissions, locks, owner, size, attributes, modified/ created times and more.
By default, NetworkOpenedFiles simply displays everything Windows provides. This could mean you see multiple entries with the same file name, user and computer name, but if this is confusing, clicking Options > Display Mode > Merge... will combine them into one.
You're also able to view the same information on any other computer on your network (as long as you've full administrator rights). Just click Options > Advanced Options, select "Load opened network files from remote computer" and enter the appropriate computer name.
An easy way to find out what other network users are doing on your PC.