To send a file to all participants in your meeting, click the Transfer File button at the bottom of the window or press Ctrl+F. (Alternatively, open the Tools menu and choose File Transfer.) To send a file only to a particular person, choose that person's name from the list in the upper right corner of the File Transfer dialog box.
Files that are sent to you are stored by default in the Received Files folder, a subfolder of your NetMeeting folder. You can change that location by choosing Change Folder from the File menu in the File Transfer dialog box. You can use the View Received Files button in the File Transfer dialog box to open your Received Files folder in Windows Explorer.