Hi. I have a dual boot system with Windows 10 and Windows 8. I had used Easy BCD for skipping the boot menu. Then I tried to install Windows 7 over Windows 8 and besides Windows 10. The Windows 7 setup failed to install Windows 7 and when I rebooted my computer it shows me error 0xc000000f. How to resolve this as I do not have Windows installation disk as well as another computer. Now how can I access windows 8 ? How can I increase the boot menu time ? I can't boot into Windows . Thank you in advance.