To use passive scanning,
1) Put the lsclient.exe in a shared folder accessible to all computers.
2) Make a batch file with the only line being : \\fileserver\share\lsclient.exe lsserver (replace fileserver with the name of your file server, replace lsserver with the name of the server Lansweeper is on)
3) Create a User Policy that runs the batch file on login and apply to all users.
To use the active scanning, refer to the documentation.