diff --git a/CHANGELOG b/CHANGELOG
index 94d5b64..c6032e2 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,6 @@
+Ver.1.0.4:
++ added Qt5 gui (by default)
+
 Ver.1.0.3:
 + [plasmoid] edited russian translation
 * [all] refactoring
diff --git a/sources/CMakeLists.txt b/sources/CMakeLists.txt
index 2b53144..ff4c3ee 100644
--- a/sources/CMakeLists.txt
+++ b/sources/CMakeLists.txt
@@ -8,13 +8,14 @@ cmake_policy (SET CMP0015 NEW)
 project (netctl-gui)
 set (PROJECT_VERSION_MAJOR 1)
 set (PROJECT_VERSION_MINOR 0)
-set (PROJECT_VERSION_PATCH 3)
+set (PROJECT_VERSION_PATCH 4)
 set (PROJECT_VERSION ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}.${PROJECT_VERSION_PATCH})
 configure_file (${CMAKE_SOURCE_DIR}/version.h.in ${CMAKE_CURRENT_BINARY_DIR}/version.h)
 
 message (STATUS "Version: ${PROJECT_VERSION}")
 
 # install options
+option (USE_QT5 "Use Qt5 instead of Qt4" ON)
 option (BUILD_GUI "Build GUI" ON)
 option (BUILD_DATAENGINE "Build data engine" ON)
 option (BUILD_PLASMOID "Build plasmoid" ON)
@@ -33,13 +34,12 @@ if (BUILD_PLASMOID)
   set (BUILD_DATAENGINE ON)
 endif ()
 
-add_subdirectory (icons)
 if (BUILD_GUI)
   add_subdirectory (gui)
 endif ()
-# if (BUILD_DATAENGINE)
-#   add_subdirectory (dataengine)
-# endif ()
-# if (BUILD_PLASMOID)
-#   add_subdirectory (plasmoid)
-# endif ()
+if (BUILD_DATAENGINE)
+  add_subdirectory (dataengine)
+endif ()
+if (BUILD_PLASMOID)
+  add_subdirectory (plasmoid)
+endif ()
diff --git a/sources/gui/src/CMakeLists.txt b/sources/gui/src/CMakeLists.txt
index 24c8873..8507db1 100644
--- a/sources/gui/src/CMakeLists.txt
+++ b/sources/gui/src/CMakeLists.txt
@@ -14,34 +14,60 @@ message (STATUS "${SUBPROJECT} Forms: ${FORMS}")
 # include_path
 include_directories (${CMAKE_SOURCE_DIR} ${CMAKE_BINARY_DIR} ${CMAKE_CURRENT_BINARY_DIR} ${CMAKE_CURRENT_BINARY_DIR}/../)
 
-find_package(Qt5Core REQUIRED)
-find_package(Qt5Widgets REQUIRED)
-find_package(Qt5LinguistTools REQUIRED)
-add_definitions(${Qt5Core_DEFINITIONS})
-add_definitions(${Qt5Widgets_DEFINITIONS})
-add_definitions(${Qt5LinguistTools_DEFINITIONS})
-qt5_wrap_cpp (MOC_SOURCES ${HEADERS})
-qt5_wrap_ui (UI_HEADERS ${FORMS})
-qt5_add_resources (QRC_SOURCES ${RESOURCES})
+if (USE_QT5)
+    find_package(Qt5Core REQUIRED)
+    find_package(Qt5Widgets REQUIRED)
+    find_package(Qt5LinguistTools REQUIRED)
+    add_definitions(${Qt5Core_DEFINITIONS})
+    add_definitions(${Qt5Widgets_DEFINITIONS})
+    add_definitions(${Qt5LinguistTools_DEFINITIONS})
+    qt5_wrap_cpp (MOC_SOURCES ${HEADERS})
+    qt5_wrap_ui (UI_HEADERS ${FORMS})
+    qt5_add_resources (QRC_SOURCES ${RESOURCES})
 
-foreach (LANGUAGE ${LANGUAGES})
-    set (TS ${SUBPROJECT_TRANSLATION_DIR}/${LANGUAGE}.ts)
-    set (QM ${SUBPROJECT_TRANSLATION_DIR}/${LANGUAGE}.qm)
-    set (TRANSLATIONS ${TRANSLATIONS} ${TS})
-    set (TRANSLATIONS_BINARY ${TRANSLATIONS_BINARY} ${QM})
-    add_custom_command (OUTPUT ${QM} COMMAND ${Qt5_LRELEASE_EXECUTABLE} ${TS} MAIN_DEPENDENCY ${TS})
-endforeach ()
-add_custom_target (translations COMMAND ${Qt5_LUPDATE_EXECUTABLE} ${HEADERS} ${SOURCES} ${UI_HEADERS} -ts ${TRANSLATIONS})
-add_custom_command (TARGET translations COMMAND ${Qt5_LRELEASE_EXECUTABLE} ${TRANSLATIONS})
-message (STATUS "${SUBPROJECT} Translations: ${TRANSLATIONS_BINARY}")
+    foreach (LANGUAGE ${LANGUAGES})
+        set (TS ${SUBPROJECT_TRANSLATION_DIR}/${LANGUAGE}.ts)
+        set (QM ${SUBPROJECT_TRANSLATION_DIR}/${LANGUAGE}.qm)
+        set (TRANSLATIONS ${TRANSLATIONS} ${TS})
+        set (TRANSLATIONS_BINARY ${TRANSLATIONS_BINARY} ${QM})
+        add_custom_command (OUTPUT ${QM} COMMAND ${Qt5_LRELEASE_EXECUTABLE} ${TS} MAIN_DEPENDENCY ${TS})
+    endforeach ()
+    add_custom_target (translations COMMAND ${Qt5_LUPDATE_EXECUTABLE} ${HEADERS} ${SOURCES} ${UI_HEADERS} -ts ${TRANSLATIONS})
+    add_custom_command (TARGET translations COMMAND ${Qt5_LRELEASE_EXECUTABLE} ${TRANSLATIONS})
+    message (STATUS "${SUBPROJECT} Translations: ${TRANSLATIONS_BINARY}")
 
-source_group ("Header Files" FILES ${HEADERS})
-source_group ("Source Files" FILES ${SOURCES})
-source_group ("Generated Files" FILES ${MOC_SOURCES})
+    source_group ("Header Files" FILES ${HEADERS})
+    source_group ("Source Files" FILES ${SOURCES})
+    source_group ("Generated Files" FILES ${MOC_SOURCES})
 
-include_directories (${Qt5Core_INCLUDE_DIRS} ${Qt5Widgets_INCLUDE_DIRS})
-add_executable (${SUBPROJECT} ${UI_HEADERS} ${HEADERS} ${SOURCES} ${MOC_SOURCES} ${QRC_SOURCES} ${TRANSLATIONS})
-target_link_libraries (${SUBPROJECT} ${Qt5Widgets_LIBRARIES} ${Qt5Core_LIBRARIES})
+    include_directories (${Qt5Core_INCLUDE_DIRS} ${Qt5Widgets_INCLUDE_DIRS})
+    add_executable (${SUBPROJECT} ${UI_HEADERS} ${HEADERS} ${SOURCES} ${MOC_SOURCES} ${QRC_SOURCES} ${TRANSLATIONS})
+    target_link_libraries (${SUBPROJECT} ${Qt5Widgets_LIBRARIES} ${Qt5Core_LIBRARIES})
+else ()
+    find_package (Qt4 REQUIRED)
+    include (${QT_USE_FILE})
+    qt4_wrap_cpp (MOC_SOURCES ${HEADERS})
+    qt4_wrap_ui (UI_HEADERS ${FORMS})
+    qt4_add_resources (QRC_SOURCES ${RESOURCES})
+
+    foreach (LANGUAGE ${LANGUAGES})
+        set (TS ${SUBPROJECT_TRANSLATION_DIR}/${LANGUAGE}.ts)
+        set (QM ${SUBPROJECT_TRANSLATION_DIR}/${LANGUAGE}.qm)
+        set (TRANSLATIONS ${TRANSLATIONS} ${TS})
+        set (TRANSLATIONS_BINARY ${TRANSLATIONS_BINARY} ${QM})
+        add_custom_command (OUTPUT ${QM} COMMAND ${QT_LRELEASE_EXECUTABLE} ${TS} MAIN_DEPENDENCY ${TS})
+    endforeach ()
+    add_custom_target (translations COMMAND ${QT_LUPDATE_EXECUTABLE} ${HEADERS} ${SOURCES} ${UI_HEADERS} -ts ${TRANSLATIONS})
+    add_custom_command (TARGET translations COMMAND ${QT_LRELEASE_EXECUTABLE} ${TRANSLATIONS})
+    message (STATUS "${SUBPROJECT} Translations: ${TRANSLATIONS_BINARY}")
+
+    source_group ("Header Files" FILES ${HEADERS})
+    source_group ("Source Files" FILES ${SOURCES})
+    source_group ("Generated Files" FILES ${MOC_SOURCES})
+
+    add_executable (${SUBPROJECT} ${UI_HEADERS} ${HEADERS} ${SOURCES} ${MOC_SOURCES} ${QRC_SOURCES} ${TRANSLATIONS})
+    target_link_libraries (${SUBPROJECT} ${QT_LIBRARIES} ${QT_QTMAIN_LIBRARY})
+endif()
 
 # install properties
 install (TARGETS ${SUBPROJECT} DESTINATION bin)
diff --git a/sources/gui/src/mainwindow.cpp b/sources/gui/src/mainwindow.cpp
index 8abc027..713acad 100644
--- a/sources/gui/src/mainwindow.cpp
+++ b/sources/gui/src/mainwindow.cpp
@@ -224,7 +224,11 @@ void MainWindow::updateMainTab()
 
     ui->tableWidget_main->setSortingEnabled(true);
     ui->tableWidget_main->resizeRowsToContents();
+#if QT_VERSION >= 0x050000
     ui->tableWidget_main->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch);
+#else
+    ui->tableWidget_main->horizontalHeader()->setResizeMode(QHeaderView::Stretch);
+#endif
     ui->tabWidget->setEnabled(true);
     ui->statusBar->showMessage(QApplication::translate("MainWindow", "Updated"));
 
@@ -284,7 +288,11 @@ void MainWindow::updateWifiTab()
 
     ui->tableWidget_wifi->setSortingEnabled(true);
     ui->tableWidget_wifi->resizeRowsToContents();
+#if QT_VERSION >= 0x050000
     ui->tableWidget_wifi->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch);
+#else
+    ui->tableWidget_wifi->horizontalHeader()->setResizeMode(QHeaderView::Stretch);
+#endif
     ui->tabWidget->setEnabled(true);
     ui->statusBar->showMessage(QApplication::translate("MainWindow", "Updated"));