What does Windows use each resolution version of an .ico for? (e.g., Start Menu, Desktop)?

A designer is making some Windows icons (.ico) for us and I want to make sure the various sizes (16px, 24px, etc.) will look Ok when Windows displays them.

I created a Test icon with a # for each size (16 for the 16x16 px version,etc.)

From my tests, Windows-7 uses:开发者_开发知识库

32 x 32 : Start menu (popup menu) 16 x 16 : Start / All Programs menu 256 x 256 : Desktop menu

Where would Windows use the 24x24?

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16 pixel icons are used by Explorer in List and Details views, in title bars, in the notification area, and in the classic taskbar.

24 pixel icons aren't usually used, although they are used by Explorer in certain zoom levels.

Note that non-standard DPIs will use different icon sizes everywhere.

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On XP, explorer uses the shell icon sizes (You can override this size in HKEY_CURRENT_USER\Control Panel\Desktop\WindowMetrics), the default sizes are 32x32 (Desktop, Icons view) and 16x16 (List and report views) @ default DPI (Note that the shell icon size might not be the same as the system icon size (used in titlebars and alt-tab etc))

The start menu panel uses 24x24 icons, the explorer toolbar also uses this size by default...