System hangs about 2 to 3 minutes during the startup process. During that time you can't access or control over the Start button, Taskbar, etc. This is because of the specific service "Background Intelligent Transfer" running in the background services.
Disabling it will avoid such things to happen at startup.
Procedure:
* Click on Start/Run, type 'msconfig', then click 'OK'.
* Go to the 'Services' tab, find the 'Background Intelligent Transfer' service.
* Disable it, apply the changes and Reboot.
That's it. Enjoy the windows.