Previously this system contains windows 7. Then two days before I installed Windows 8 Developer Preview by growing the ISO to a virtual drive and running the setup.exe. It works well but now I want to revert back to the windows 7 onto this system. There is a window 7 setup files present on the C:/Windows.old folder. Hence is it possible to restore windows 7 after installing Windows 8 Developer Preview. Any help to do this task will be appreciating.