Step 1: Type msconfig in the Start/taskbar search field and then press the Enter key to open the System Configuration dialog. Step 2: Switch to the Boot tab. Select the operating system that you want to set as the default and then click Set as default button. Click the Apply button.
How do I change my boot drive from C to D?
Find the drive letter you want changed. Look for \DosDevices\D: . Right-click \DosDevices\D: , and then select Rename. Rename it to the appropriate (new) drive letter \DosDevices\C: .