Function key F10 on Inspiron 8600

Fn+F10

Your Fn key  or  F10 key (or both) may be going bad. Try testing the Fn key by using some of the other Fn functions. Try testing the F10 key using applications that use F10 (shift+F10 , alt+F10 , ctrl+F10). Run through the diagnostics. If it still doesn't work and your under warranty call Dell. They have you go through everything again - but be persistent - and after redoing everything you may have to request a new keyboard.

The same thing happened to me with my Inspiron 5150. I went to the start menu, all programs, Dell Quickset and clicked on Quickset. A new icon appeared in the system tray at lower right. The fn+F10 now opened the CD/DVD and the sound meter and volume meter appeared when using fn to adjust volume or sound.