Windows uses .ico format unlike mac which uses .icn
The .ico you will need for windows is joint icons means multiple size and depth icon images in one single file!
You must have noticed that .ico have multiple images in it and I will teach you how to do so.
First make anything inside photoshop and make sure the size of the image is 256×256 pixels and is transparent.
Now save it as anyname.png
Start the program any to icon(download link at the bottom of the post)
drop the png file to the white area just like i did, see in the picture.
Then click on next, follow the instruction which will ask you what size’s you want ,check them out, select destination and click on next!
You will see joint icon with multiple size’s at your destination folder.