The preference dialog is divided into tabs. Each tab contains a group of related preferences.
The Main tab offers access to the most basic settings.
The Progress dialog setting controls if the progress dialog will close itself automatically.
The Overlay icons setting allows you to change the set of overlay icons used. The Browse... button causes the icon chooser dialog to be shown:
The Rebuild... button rebuilds Windows™ Explorer's icon cache. This can sometimes be necessary if the overlay icons are not showing correctly.
The Folder overlay icons setting controls if and how the overlay icon for a folder reflects the state of the files and folders inside it.
The Autoload changed folder icons setting (only applicable if you have selected something else than "Don't change icon" above) determines if the folder status is updated automatically, or only when you select from the CVS context menu in Explorer.
Finally, the Language setting allows you to change the language used for menus and dialogs.
The Policy tab...
The Advanced tab contains settings that the typical user does not need to change.
The Sandbox DOS/UNIX setting controls how line endings are preserved when doing CVS operations in an existing sandbox (as opposed to the Use UNIX line endings checkbox in the Checkout and Make new module dialogs, which controls how the sandbox is initially created).
Autodetect (default to DOS) and Autodetect (default to UNIX): TortoiseCVS checks which line ending format is used and gives the appropriate options to CVS so that the existing line ending format is preserved.
DOS and UNIX: TortoiseCVS ignores the existing line ending format and forces CVS to create the specified line ending format.