I had dual OS . Windows 7 and Windows 8. I generally go to windows 8. Today morning, I thought lets visit windows 7 since it has been long time there. I choose windows 7 from dual OS menu and go there. but I find its de-activated. So I used windows loader to activate again. I worked on windows 7. when I reboot to go to windows 8 again, I find there is no Dual OS option. It is starting windows 7 directly. I open msconfig of windows 7 and under boot tab, there is no windows 8 !! only 7.... can u please tell me a way to get back that dual OS menu .... I dont want to reinstall windows 8 again !!