Install the classic icon.

setup.iss

@@ -126,6 +126,7 @@ Source: "files\Setup.e32"; DestDir: "{app}"; Flags: ignoreversion touch
 Source: "files\SetupLdr.e32"; DestDir: "{app}"; Flags: ignoreversion touch
 Source: "files\Default.isl"; DestDir: "{app}"; Flags: ignoreversion touch
 Source: "files\Languages\*.isl"; DestDir: "{app}\Languages"; Flags: ignoreversion touch
+Source: "files\SetupClassicIcon.ico"; DestDir: "{app}"; Flags: ignoreversion touch
 Source: "files\WizModernImage.bmp"; DestDir: "{app}"; Flags: ignoreversion touch
 Source: "files\WizModernImage-IS.bmp"; DestDir: "{app}"; Flags: ignoreversion touch
 Source: "files\WizModernSmallImage.bmp"; DestDir: "{app}"; Flags: ignoreversion touch