Welcome to Tom's Hardware Forums,
Gonna suggest trying F12 or delete (delete doesn't usually work on Dells though)
I did find your manual which shows that on some models - not specific, you can depress the FN&F1 keys while in windows to access the BIOS? Weird - pg 120
http://support.dell.com/support/edocs/systems/ins8200/en/1H018bk3.pdf
See if any of that helps
Also, when trying to access BIOS - tap the key continually until you get into BIOS (doesn't hurt anything if you're still tapping it in BIOS - just makes funny sounds)