diff --git a/installer/xsystem35.nsi b/installer/xsystem35.nsi
index c3234ac..27a3fcb 100644
--- a/installer/xsystem35.nsi
+++ b/installer/xsystem35.nsi
@@ -13,6 +13,13 @@ UninstPage instfiles
 
 LicenseData ..\COPYING
 
+!define SHCNE_ASSOCCHANGED 0x08000000
+!define SHCNF_IDLIST 0
+Function RefreshShellIcons
+	System::Call 'shell32.dll::SHChangeNotify(i, i, i, i) v \
+		(${SHCNE_ASSOCCHANGED}, ${SHCNF_IDLIST}, 0, 0)'
+FunctionEnd
+
 Section
 	SetOutPath $INSTDIR
 	FILE ${BUILDDIR}\src\xsystem35.exe
@@ -33,8 +40,9 @@ LangString FileAssociation ${LANG_JAPANESE} ".ALD ファイルに関連付け"
 Section "$(FileAssociation)"
 	WriteRegStr HKCR ".ald" "" "System35Archive"
 	WriteRegStr HKCR "System35Archive" "" "AliceSoft System 3.x archive"
-	WriteRegStr HKCR "System35Archive\DefaultIcon" "" "$INSTDIR\xsystem35.exe,1"
+	WriteRegStr HKCR "System35Archive\DefaultIcon" "" "$INSTDIR\xsystem35.exe,0"
 	WriteRegStr HKCR "System35Archive\shell\open\command" "" '"$INSTDIR\xsystem35.exe" "%1"'
+	Call RefreshShellIcons
 SectionEnd
 
 LangString DesktopIcon ${LANG_ENGLISH} "Create Desktop icon"
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a3bb804..dd62bcc 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -65,7 +65,7 @@ target_sources(xsystem35 PRIVATE
   network.c)
 
 if (WIN32)
-  target_sources(xsystem35 PRIVATE win/dialog.c)
+  target_sources(xsystem35 PRIVATE win/dialog.c win/resources.rc)
 endif()
 
 if (EMSCRIPTEN)
diff --git a/src/win/resources.rc b/src/win/resources.rc
new file mode 100644
index 0000000..2b0fcd5
--- /dev/null
+++ b/src/win/resources.rc
@@ -0,0 +1 @@
+100 ICON DISCARDABLE "xsystem35.ico"
diff --git a/src/win/xsystem35.ico b/src/win/xsystem35.ico
new file mode 100644
index 0000000..b7beb2d
Binary files /dev/null and b/src/win/xsystem35.ico differ