F3: List file contents
Select the files you want to list and press F3. The built in file viewer (called lister) then shows the selected files, or the file under the cursor (as configured). By holding down the SHIFT key and pressing F3, you select the alternative method (i.e. view selected files when the default is the file under the cursor). In lister, you can switch from file to file (when viewing multiple files) by pressing n, ESC closes lister and returns to Total Commander. You can also configure Total Commander to show the files with an external viewer of your choice.
With ALT you can switch between external and internal viewer, and with SHIFT between one and multiple files (multiple only with internal viewer). With ALT+SHIFT+F3, lister starts without loading any plugins or multimedia views.
If the source directory shows the contents of an archive, the files will be unpacked automatically for viewing. The files are unpacked to the directory determined by the environment variable temp. You can set it via Control Panel, for example to c:\temp. If this directory does not exist, Total Commander's program directory is used. A subdirectory \_tc is created, where all temporary files are stored. When Total Commander is closed, this directory is removed (provided it is empty).