I have a Lenovo Ideapad Z series Windows 8 Laptop. Recently after a Windows update, my laptop is behaving erratically. During startup, the screen flashes black for a second before the Windows 8 homepage loads. Also, all browsers (IE/Chrome) as well as other pages, like windows explorer, word, excel etc. flicker whenever they are loaded, particularly when minimized and maximized. The screen flickers black for a moment. I tried a system restore but the problem persists. All drivers are also up to date. Any solutions?