When you install two operating systems on your computer, the computer's master boot record, or MBR, notes both operating systems and allows you to choose which one boots automatically.To avoid data loss, you can create a backup of your MBR. If you do not intervene when the computer first starts, you can choose which one starts when you turn on your computer. More than one operating system installed on a computer is often called a multiboot configuration. Multi-boot or Multi-booting is the act of installing multiple operating systems on a computer, and being able to choose which one to boot when starting the computer To change which operating system has boot priority, you must modify the settings in your system properties.
There are several reasons for installing two operating system on your computer
• You want to run a "gaming machine" as well as a "business machine" on the same computer.
• Web designers want to view their work on various operating systems and their native web browsers.
• A piece of legacy hardware, such as a scanner, works on Windows 98, but not in Windows XP.
• IT staff need to be able to work with older as well as new versions of Windows.
• You want to experiment with an operating system like Linux, but need to be able to use Windows as your main operating system.
Steps to Change the Default operating system for startup
• Open System by clicking the Start button , clicking Control Panel, clicking System and Maintenance, and then clicking System.
• Click Advanced System Settings. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
• Click the Advanced tab, and then, under Startup and Recovery, click Settings.
• Under System startup, in the Default operating system list, click the operating system that you want to use when you turn on or restart your computer.
See also: How to Resolve Windows 7 BOOTMGR Missing Error
