Stuck at Dell Logo Screen

I've tried everything but my laptop is stuck on the DELL logo screen with the bar under "Studio" 3/4 loaded. 1. Rebooting and hitting F2 or F12 or F5 or F8 nothing happens still 3/4 loads. 2. Removed battery and use power cord, reboot - Still 3/4 loads 3. Removed power cord and use batter...