Dell Inspiron 1720 Owner's Manual page 135

4 Restart the computer.
When the DELL logo appears, press <F12> immediately.
NOTE:
If you wait too long and the operating system logo appears, continue
to wait until you see the Microsoft Windows desktop, then shut down your
computer and try again.
NOTE:
The next steps change the boot sequence for one time only. On the
next start-up, the computer boots according to the devices specified in the
system setup program.
5 When the boot device list appears, highlight CD/DVD/CD-RW Drive,
and then press <Enter>.
6 Press any key to Boot from CD-ROM.
7 Follow the instructions on the screen to complete the installation.
Troubleshooting
135