Sort of a follow up to my previous how to guide on restoring the Windows 7 MBR, I thought it would also be helpful to show a quick guide on making Windows 7 the default operating system to boot into. As you know, when you have a dual boot setup, you will be prompted at startup as to which installation you would like to boot into, but after a short countdown, it will default to one of the operating systems. Here is how to tell the system which one to use by default.
Open the Start Menu and right-click on Computer and click on Properties.
The System window should open and you will click on Advanced system settings on the right-hand task pane.
Under the Advanced tab, click on the Settings button under Startup and Recovery.
Under System Startup, select a operating system from the drop down menu to be the new default operating system, then click on OK.
Click on OK.
Another quick way to do the same thing is to click on the Start menu and type msconfig into the search box and hit Enter.
Click on the Boot tab.
Select the installation you wish to boot into by default and check the Make all boot settings permanent box.
Click OK.
Hope this is helpful. I’m currenty dual booting Windows 7 and Vista on one machine and Windows 7 and Mac OSX Leopard on another. What are you dual booting?