The tab Scan Options allows you to configure the file search in different ways.
Drives and Paths to include
Use the check boxes in front of each drive to select which paths should be searched by the file search. You can add additional paths and network drives using the buttons below the list. The first button will allow you to type in a path, the second one will open a folder browser dialog.

You can search entire servers or PCs by using their UNC name like \\SERVER. You can search your entire domain by using its UNC name, e.g. \\DOMAIN. You can even search you entire network by choosing the network neighborhood of Windows in the directory browser that appears after pressing Browse and Add Path. TreeSize Professional automatically browses for PCs and all shares on them (including hidden shares) and performs the search on all shares that it finds.
Enabled Search Types
Use the check boxes in front of each item to enable or disable certain search types. Each search type will be represented by a separate register.
The file search was designed to identify obsolete or very large files in order to clean up a system. Certain files like system files should however not be deleted because they are necessary for the operating system or other software to run. Files known to be important for a system can be added to the exclude list here and will then not be shown in the results any more. New entries in this list can be easily added using the right click menu of the result lists.

Additionally you may exclude files that have been changed in the past hours. If a file has been changed recently there is a high probability that the file is not truly obsolete.
Please note: This option will by default NOT be applied to the duplicate file search and to the custom file search. However, you can enable it by check-marking the corresponding check-boxes on the registers of the duplicate search and the custom file search.

