Are you trying to create a shortcut? "C:\Program Files (x86)\Mozilla Firefox_Curr\firefox.exe" YouTube.com https://developer.mozilla.org/en-US/docs/Mozilla/Command_Line_Options This is an archived page. It's not actively maintained. -private Opens Firefox in permanent private browsing mode. Firefox 3.6 and later only. May not be applicable in older Ubuntu for Firefox 20 and later, confirmed to work in 14.04. -private-window Opens a new private browsing window in an existing instance of Firefox. Firefox 20 and later only. -private-window URL Open URL in a new private browsing window. If a private browsing window is already open, a new tab is opened in the existing window. Firefox 29 and later only. Does not work in Firefox 31 on linux mint 17 nor on Firefox 48 on Windows 7. URL opens in a non-private window.