@kabir96: You can already customize the icon of any program on Windows.
Create a shortcut for the program -> right click the shortcut -> Properties -> Change icon -> Browse. You can pick any .ico file.
In order to pin it to the taskbar right click the shortcut -> Show more options (if on Windows 11) -> Pin to taskbar. If the program was already pinned, you will see Unpin from taskbar. Unpin it and then pin the shortcut.