nogames, Not positive but by removing the coin cell battery may clear cmos. Good luck.
I hope this helped you out, if so let me know by pressing the helpful button.
Use the links below to learn of the 3 methods to reset Nvram .
http://en.community.dell.com/support-forums/desktop/f/3514/t/17592640
http://www.dell.com/support/Article/ca/en/cabsdt1/SLN284985