Setting Default OS to boot in Vista and Windows 7

To set the default OS (in case of dual boot Windows OS) to be either Vista or Windows 7, do the following
1. Click "My Computer" - > Properties (You can also go here from "Control Panel"->"System")

2. Click on "Advanced System Settings" on the left side panel (This will open "Advanced" tab in "System Properties" dialog)

3. Click on "Settings" of "Startup and Recovery" group

4. Select the "Default Operating System" in "System Startup" group