Dell OptiPlex E1 - Manual (Page 29)

Responding to Error Messages
If an error message appears on your monitor screen while the system is booting, make note of the message. Then, before entering
the System Setup program, refer to your Diagnostics and Troubleshooting Guide for an explanation of the message and
suggestions for correcting any errors. However, it is normal to receive an error message the first time you boot the system after a
memory upgrade. In that case, you do not need to refer to the Diagnostics and Troubleshooting Guide; instead, refer to the
instructions in "
Adding Memory " in this guide.
If you are given an option of pressing either <F1> to continue or < F2> to run the System Setup program, press the <F2> key.