If you have more than one operating system installed on your computer then you may choose which one to start when you turn on or when you restart your computer. Perform the following steps to change the default operating system for startup: 1. Click the Start button . Right-click Computer and then click Properties. 2. From the left pance, click Advanced system settings (If you are prompted for an administrator password or confirmation, type the password or provide confirmation). 3. Click on the Advanced tab. 4. Under Startup and Recovery, click Settings... 5. 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. 6. Click OK to close Startup and Recovery dialog box. 7. Click Apply and then click Close to dismiss the System Properties dialog box.

If you are planning to setup your computer as an entertainment hub then you may consider setting up Windows Media Center to automatically start as soon as the boot process gets complete. Perform the following steps to start Windows Media Center automatically when you start your Windows 7 based computer:
1. Open Windows Media Center by clicking the Start button , clicking All Programs and then clicking Windows Media Center. You may also open Windows Media Center by clicking Start button , typing Windows Media Center in the Search programs and files box and then clicking Windows Media Center from the Programs list.
2. From the Windows Media Center start screen, scroll and click Tasks and then click Settings.
3. Click General and then click Startup and Window Behavior.
4. From the STARTUP AND WINDOW BEHAVIOR screen, click to place a checkmark beside Start Windows Media Center when Windows starts and then click Save.