Stuck at Preparing to enter setup

[langle1033]

When I power on, my Dell 7240 Win 8.1 get stucks at Dell Logo, if I hit F2 then on the top right corner will display" Preparing to enter Setup..." If I hit F8 then it ask me to hit F12 and the msg "preparing onetime setup" appears. I tried to remove battery, SSD but no luck. I called Dell but no solution either. What should I do ? Thanks

 

[amd4lif3]

hold the power buttion so it turns off then take out the battery whilst still having your finger still pressing the power button keep doing this for 2 mins then take your finger off the button put the battery in and try it

 

[langle1033]

hold the power buttion so it turns off then take out the battery whilst still having your finger still pressing the power button keep doing this for 2 mins then take your finger off the button put the battery in and try it

Thanks for the suggestion, however it still stucks at those screens. I tried both with battery and without battery (just the charger). I also tried to hold my finger more than 2 min.

 

[langle1033]

Final Report: I have to remove CMOS battery for 30 sec. Then I have to refresh the laptop to old Win 8 Pro version and all other files.

Now I lost my Win 8.1 upgrade plus my backlit keyboard function stops working but everything else seems OK
My next step is find out how to get the backlit keyboard and win 8.1 back. If you have any idea, please help.

Thanks