You may toggle that behaviour on/off in Dell Media Center or in BIOS. AFAIK, I’m afraid it’s all or nothing and cannot be changed on a per key basis. 

Exact same issue, if i press Home or End then instead of the cursor moving to begin/end of line i get the F11/F12 function key effect. 

I thought the fn (function) key was stuck down, but no, pressing the key makes the "correct" key work. 

e.g.

Screen Brighter -> fn + f7 ,   and if i want f7 i just need to press the screen brighter key. 

End key ->  fb + end, and if i want F12 i just need to press End key. 

As per original poster the fn key is "reversed".  Rather annoying. 

You may toggle that behaviour on/off in Dell Media Center or in BIOS. It’s your choice. 

Hello... use the FN and F1 or ESC key (this the small lock symbol on it) to switch to normal F1-F12 mode
hth

Peter

Indeed, there is no switching in BIOS (as far as my test goes), but try this solution.

• To switch between fn-keys meanings (assignments), press:
  • fn+Esc for functions, or hit
  • fn+Esc again for F-keys.

Clear? This command will switch the meanings.

This information should at least be available through some Windows settings or information IMO.

@DellM68324​ thanks mate