To add a log file you wish to view in the list, select File => Open. This will display the Open Log window where you can select the directory and filename of the log file you wish to view.The figure below illustrates the Open Log window.

Click on the Open button to open the file. The file is immediately added to the viewing list where you can select it and view the contents.

Please also note that the System Log Viewer also allows you to open zipped logs whose filenames end in ".gz".