File Opened By?

Under NT 4.0 I was able to use the old application File Manager to select a single file on the network, check the properties and hit a button to tell me all the users that had the file open.

Under Win2k the File Manager exe has been removed, but you can copy it back from a Win NT machine. It works fine except that the button to display the users that have it open does not work.

Any ideas or replacement utilities?

PS: the person logged in must have Admin access.