diff --git a/libs/functions.py b/libs/functions.py
index ec072d7..efd99b6 100644
--- a/libs/functions.py
+++ b/libs/functions.py
@@ -24,7 +24,7 @@ from libs.Kernel import Kernel, InstalledKernel, CommunityKernel
 from ui.MessageWindow import MessageWindow
 from queue import Queue
 import gi
-gi.require_version("Gtk", "3.0")
+gi.require_version("Gtk", "4.0")
 from gi.repository import GLib
 
 
diff --git a/snigdhaos-kernel-switcher.css b/snigdhaos-kernel-switcher.css
new file mode 100644
index 0000000..e69de29
diff --git a/snigdhaos-kernel-switcher.py b/snigdhaos-kernel-switcher.py
index c28ff2d..59ceb7a 100644
--- a/snigdhaos-kernel-switcher.py
+++ b/snigdhaos-kernel-switcher.py
@@ -1,6 +1,7 @@
-#!/usr/bin/python
+#!/bin/python
 import os
 import libs.functions as fn
+from ui.ManagerGUI import ManagerGUI
 import gi
 gi.require_version("Gtk", "4.0")
 from gi.repository import Gtk, Gio, GLib, Gdk
@@ -20,4 +21,33 @@ class Main(Gtk.Application):
         super().__init__(application_id=app_id, flags=Gio.ApplicationFlags.FLAGS_NONE)
     
     def do_activate(self):
-        default_context = GLib.
\ No newline at end of file
+        default_context = GLib.MainContext.default()
+        win = self.props.active_window
+        if not win:
+            win = ManagerGUI(application=self, app_name=app_name, default_context=default_context,app_version=app_version)
+        display = Gtk.Widget.get_display(win)
+        win.set_icon_name("snigdhaos-kernel-switcher-tux")
+        provider = Gtk.CssProvider.new()
+        css_file = Gio.file_new_for_path(css_file)
+        Gtk.StyleContext.add_provider_for_display(display, provider, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION)
+        win.present()
+
+    def do_startup(self):
+        Gtk.Application.do_startup(self)
+    
+    def do_shutdown(self):
+        Gtk.Application.do_shutdown(self)
+        if os.path.exists(lock_file):
+            os.remove(lock_file)
+        if os.path.exists(pid_file):
+            os.remove(pid_file)
+        if os.path.exists(progress_lock_file):
+            os.remove(progress_lock_file)
+    
+    def snigdhal_handler(sig, frame):
+        Gtk.main_quit(0)
+    
+    # if __name__ == "__main__":
+    #     try:
+    #     except Exception as e:
+    #         return False
\ No newline at end of file