diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..1c59f0a
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,83 @@
+cmake_minimum_required(VERSION 3.5)
+
+project(CuteSchedule VERSION 0.1 LANGUAGES CXX)
+
+set(CMAKE_AUTOUIC ON)
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+find_package(QT NAMES Qt6 Qt5 REQUIRED COMPONENTS Widgets)
+find_package(Qt${QT_VERSION_MAJOR} REQUIRED COMPONENTS Widgets)
+
+file(GLOB_RECURSE PROJECT_SOURCES "src/**.cpp" "src/**.cxx" "src/**.h" "src/**.hpp")
+list(APPEND PROJECT_SOURCES "main.cpp")
+
+if(${QT_VERSION_MAJOR} GREATER_EQUAL 6)
+    qt_add_executable(CuteSchedule
+        MANUAL_FINALIZATION
+        ${PROJECT_SOURCES}
+    )
+# Define target properties for Android with Qt 6 as:
+#    set_property(TARGET CuteSchedule APPEND PROPERTY QT_ANDROID_PACKAGE_SOURCE_DIR
+#                 ${CMAKE_CURRENT_SOURCE_DIR}/android)
+# For more information, see https://doc.qt.io/qt-6/qt-add-executable.html#target-creation
+else()
+    if(ANDROID)
+        add_library(CuteSchedule SHARED
+            ${PROJECT_SOURCES}
+        )
+# Define properties for Android with Qt 5 after find_package() calls as:
+#    set(ANDROID_PACKAGE_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/android")
+    else()
+        add_executable(CuteSchedule
+            ${PROJECT_SOURCES}
+        )
+    endif()
+endif()
+
+# --- External projects include --- #
+# Add yaml-cpp
+include(ExternalProject)
+set(EXTERNAL_INSTALL_LOCATION ${CMAKE_BINARY_DIR}/external)
+
+ExternalProject_Add(yaml-cpp-src
+    GIT_REPOSITORY "https://github.com/jbeder/yaml-cpp"
+    CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${EXTERNAL_INSTALL_LOCATION}
+)
+
+include_directories(${EXTERNAL_INSTALL_LOCATION}/include)
+link_directories(${EXTERNAL_INSTALL_LOCATION}/lib)
+
+add_library(yaml-cpp UNKNOWN IMPORTED)
+add_dependencies(CuteSchedule yaml-cpp-src)
+
+set_target_properties(yaml-cpp PROPERTIES
+    IMPORTED_LOCATION ${EXTERNAL_INSTALL_LOCATION}/lib/libyaml-cpp.a
+)
+
+# --- End external projects --- #
+
+target_link_libraries(CuteSchedule
+    PRIVATE
+    Qt${QT_VERSION_MAJOR}::Widgets
+    yaml-cpp
+)
+
+set_target_properties(CuteSchedule PROPERTIES
+    MACOSX_BUNDLE_GUI_IDENTIFIER my.example.com
+    MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION}
+    MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
+    MACOSX_BUNDLE TRUE
+    WIN32_EXECUTABLE TRUE
+)
+
+install(TARGETS CuteSchedule
+    BUNDLE DESTINATION .
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
+
+if(QT_VERSION_MAJOR EQUAL 6)
+    qt_finalize_executable(CuteSchedule)
+endif()
diff --git a/main.cpp b/main.cpp
index 1af76c2..3939866 100644
--- a/main.cpp
+++ b/main.cpp
@@ -12,24 +12,31 @@
 #endif
 
 #include <QApplication>
+#include <QErrorMessage>
 
 #include <iostream>
 
 #include "src/config/config.h"
-#include "src/sysutil.h"
 #include "src/mainwindow.h"
+#include "src/util/userutil.h"
 
 int main(int argc, char *argv[])
 {
+    QApplication a(argc, argv);
+
     Config config;
 
-    std::cout << config.loadDefaultConfig() << '\n';
-    return 0;
+    if (!config.loadDefaultConfig()) {
+        UserUtil::showError(
+            QString("Cannot load config:\n") +
+            "\n" +
+            "Error code: 0x" + QString::number(config.getLastErrorCode()) + "\n"
+        );
+        return config.getLastErrorCode();
+    }
 
-    QApplication a(argc, argv);
     MainWindow w;
     w.show();
 
-
     return a.exec();
 }
diff --git a/src/config/config.cpp b/src/config/config.cpp
index d748459..c095372 100644
--- a/src/config/config.cpp
+++ b/src/config/config.cpp
@@ -4,3 +4,40 @@ Config::Config()
 {
 
 }
+
+bool Config::loadDefaultConfig()
+{
+    QString confDir = Config::getDefaultConfigDir();
+    QDir configs(confDir);
+
+    if (!configs.exists())
+    {
+        this->errorCode = CONF_ERR_NO_DIR;
+        return false;
+    }
+
+    return true;
+}
+
+QString Config::getDefaultConfigDir()
+{
+#ifdef _WIN32
+    return QString("C:\\Users\\") + SysUtil::getUserName() + "\\AppData\\Local\\CuteSchedule";
+#endif
+
+#ifdef linux
+    return QString("/home/") + SysUtil::getUserName() + "/.config/CuteSchedule";
+#endif
+
+    return "";
+}
+
+QString Config::getConfigProperty(QString path)
+{
+    return "";
+}
+
+int Config::getLastErrorCode()
+{
+    return this->errorCode;
+}
diff --git a/src/config/config.h b/src/config/config.h
index def04db..7bbf68e 100644
--- a/src/config/config.h
+++ b/src/config/config.h
@@ -2,11 +2,29 @@
 #define CONFIG_H
 
 #include <QObject>
+#include <QDir>
+#include <yaml-cpp/yaml.h>
+
+#include "../util/sysutil.h"
+
+#define CONF_ERR_NO_DIR 1
 
 class Config
 {
+private:
+    QString plainConfig;
+    YAML::Node config;
+    int errorCode;
 public:
     Config();
+    int getLastErrorCode();
+
+    // Files
+    bool loadDefaultConfig();
+    static QString getDefaultConfigDir();
+
+    // Config
+    QString getConfigProperty(QString path);
 };
 
 #endif // CONFIG_H
diff --git a/src/sysutil.cpp b/src/util/sysutil.cpp
similarity index 100%
rename from src/sysutil.cpp
rename to src/util/sysutil.cpp
diff --git a/src/sysutil.h b/src/util/sysutil.h
similarity index 100%
rename from src/sysutil.h
rename to src/util/sysutil.h
diff --git a/src/util/userutil.cpp b/src/util/userutil.cpp
new file mode 100644
index 0000000..f797a81
--- /dev/null
+++ b/src/util/userutil.cpp
@@ -0,0 +1,14 @@
+#include "userutil.h"
+
+UserUtil::UserUtil()
+{
+
+}
+
+void UserUtil::showError(QString message)
+{
+    QMessageBox box;
+    box.critical(0, "Error", message);
+    // box.setFixedSize(500,200);
+    box.show();
+}
diff --git a/src/util/userutil.h b/src/util/userutil.h
new file mode 100644
index 0000000..1f8e18c
--- /dev/null
+++ b/src/util/userutil.h
@@ -0,0 +1,18 @@
+#ifndef USERUTIL_H
+#define USERUTIL_H
+
+#include <QObject>
+#include <QString>
+
+#include <QMessageBox>
+
+class UserUtil : public QObject
+{
+    Q_OBJECT
+public:
+    UserUtil();
+
+    static void showError(QString message);
+};
+
+#endif // USERUTIL_H