How do you set Windows 2000 as the default operating system on a dual-boot machine? You have 2 choices:
Right-click "My Computer," select "Properties," "Advanced" tab in the "Startup and Recovery" section, hit the "Startup and Recovery..." button.
In the "Default Operating System" section, select Win2k from the drop-down list.
Edit the hidden system file 'c:boot.ini'...
Assuming you have Win2k installed to C:WINNT, just change the "default=" which is under "[bootloader]" to: