happyinhawaii 

Try clearing the 'Event Log' in the system setup and see if that makes a difference.

 Restart the system now and press the F2 key as the Blue Dell logo appears.

After that the system setup screen will appear, on that screen, go to the "Maintenance" option and then press enter.

Under that there is one option for the "Event Log". Select that and press enter. Then select the option “Clear Log”.

After that select the option “load defaults”, select the option “Continue”.

After that press the "ESC" button from the keyboard and select the option that says "SAVE/EXIT".

Bev.

Thanks for the suggestion.  I tried exactly what you said but still got the error on booting my pc this morning.

I googled this error message and was shocked to see how many people get the same error message.  So far, though, I haven't found any other solution to try.

Dell uses a custom CPU cooling fan that has some extra electronics that "report" to the BIOS.  Assuming you have the original Dell fan it would appear the electronics in the fan have failed, even though the fan is working. 

This is an extra safety feature that Dell uses in case a fan does fail the user will see the failure and avoid potential harm to the PC (CPU).  However, in this case it would appear the "safety feature" has failed rather than the actual fan.

One thing to try is "reseat" the fan connection to the motherboard.  Reseat - with the PC powered off, open the case and disconnect the fan connection to the motherboard then reconnect the fan making sure it's fully and correctly reinstalled.  Power the PC back on and see if you still get the fan failure notice.  If not, it was just a bad connection.

HERE is the Dell drawing of the motherboard showing where the CPU fan is connected. 

If you decide to replace the fan, HERE is the Dell "spare parts" access form.