UFT Pro (LeanFT) .NET SDK Reference, Version 14.03
CloseAllTabs Method
Closes all tabs (if any) and closes the browser window.
Remarks

Use the Close method to close only the currently open tab.

Limitation: Your Internet Explorer (IE) browser must be configured to "Always close all tabs". To do this, open two or more tabs in IE. Then close IE. In the message box that pops up, select the "Always close all tabs" option.

Note: This method is not supported on Chrome. Use the Close method instead.

Syntax
void CloseAllTabs()