I have installed Windows 7 on my Mac via Boot Camp.
Now I don't know how to eject the Windows 7 install DVD from within Windows. The system is booting into Windows.
If you are in Windows already: you can right click a CD in My Computer and choose Eject from the menu options.
If you want to eject before booting into Windows, just reboot and hold the left mouse key while rebooting, this is the force disk eject option.