Extract icons from Windows executable

There are a number of tools you can use.

icoutils, available as the eponymous package in many distributions, includes a tool capable of extracting resources from most Windows executables, wrestool.

wrestool -x --output=. -t14 /path/to/windows.exe

will extract the icons present in the given Windows executable and write them to individual files, named after the executable name, with the type and icon name added.

7z can also extract all the resources in a Windows executable;

7z x /path/to/windows.exe .rsrc/ICON

will extract all the icons in the given Windows executable and write them to individual files in the .rsrc/ICON directory.