What is clean installation and Dual boot Installation

Clean Installation

Windows 7 clean installation is done on an unused partition on your hard drive. A clean installation of Windows 7 means remove an existing operating system and replace it with a fresh installation of Windows 7 or installation of windows 7 in a new PC recently installed. It is also known as customized installation

Dual Boot Installation

Dual boot installation allows you to install more than one operating systems on the same computer. For example: You can boot your PC between Windows XP and Windows 7 or between Windows Vista and Windows 7. You can select the operating system that you want to boot from the Windows Boot Manager. The Windows Boot Manager screen appears as shown in Figure

Each operating system has its own partition on hard disk drive. If you install earlier versions of windows such as Windows XP or Vista after installing Windows 7, the installation process of the earlier Windows operating system does not recognize the Windows XP or Vista operating system and the computer boots only earlier version of Windows only.

note:

When you configure your computer to boot between multiple operating systems, you should install the operating system in the order in which they are released by Microsoft.

In dual boot system, you can install Windows 7 through an installation media or run the installation set up through previous version of Windows that has been installed already. When you configure your computer to dual boot with Windows 7, you will get a wizard to select the type of installation you want as shown in the Figure

Select Custom AdvanceInstallation type to make the system dual boot with windows

NoteWhen you configure a computer to dual boot with window 7 , the installation process is same as that of clean installation

To dual boot your computer between Windows 7 and previous version of Windows, you should assign free space in system volume partition to accommodate each operating system. To dual boot with Windows 7 you should have at least 15 GB of free space in the existing volume in your computer. If you don't have spare partitions on your computer, you can create new volumes on existing volumes using disk management console.