Dell Inspiron 1720 (Mid 2007) - Manual (Page 101)

Troubleshooting
101
Starting the Dell Diagnostics From the Drivers and Utilities Media
1 Insert your Drivers and Utilities media.
2 Shut down and restart the computer.
3 When the DELL logo appears, press <F12> immediately.
NOTE:
Keyboard failure may result when a key on the keyboard is held down
for extended periods of time. To avoid possible keyboard failure, press and
release <F12> in even intervals until the boot device menu appears.
4 At the boot device menu, use the up- and down-arrow keys to highlight
CD/DVD/CD-RW, and then press <Enter>.
NOTE:
The Quickboot feature changes the boot sequence for the current
boot only. Upon restart, the computer boots according to the boot sequence
specified in system setup.
5 Select the Boot from CD-ROM option from the menu that appears, and
then press <Enter>.
6 Type 1 to start the Drivers and Utilities menu, and then press <Enter>.
7 Select Run the 32 Bit Dell Diagnostics from the numbered list. If
multiple versions are listed, select the version appropriate for your
computer.
8 At the Dell Diagnostics Main Menu, select the test you want to run.
NOTE:
Write down any error codes and problem descriptions exactly as they
appear and follow the instructions on the screen.
9 After all tests have completed, close the test window to return to the Dell
Diagnostics Main Menu.
10 Remove your Drivers and Utilities media, then close the Main Menu
window to exit the Dell Diagnostics and restart the computer.