* Nuclear Fusion: The process that powers stars, fusing hydrogen atoms into helium, occurs at extremely high temperatures and pressures. Water vapor is not involved.

* Chemical Reactions (Many): While some chemical reactions do involve water, many others do not. For example, the reaction of sodium with chlorine to form sodium chloride (table salt) does not involve water vapor.

* Physical Processes in a Vacuum: Processes in a vacuum, such as the operation of certain scientific instruments or space exploration, would not involve water vapor.

* Certain Geological Processes: Some deep geological processes, such as the formation of certain minerals or the movement of tectonic plates, may not directly involve water vapor.

Important Note: While these processes may not directly involve water vapor, they might occur in environments where water vapor is present. However, the processes themselves do not require water vapor.