Where is the majority of the earths fresh water stored?

Glaciers and icecaps.
about 2/3 of Earth's fresh water is stored in polar ice caps and glaciers, while the rest are in freshwater streams and rivers running towards the ocean.
Under ground

The largest percentage of SURFACE fresh water is stored in the polar ice caps. If you would like your water as a liquid, go to the Great Lakes- they contain 21% of the world's surface fresh water.
The ice caps, namely the North and South Pole. Most fresh water is frozen solid. The largest reservoirs of liquid fresh water on earth are the Great Lakes.
In the polar ice caps