bakra

Hello. I need help with my Alienware M17x-R4. I can't remember pre-boot password. I tried removing BIOS battery and leaving lap-top without power for all night. I removed CPU, battery and turned it on. Tried pushing for power button for 30 seconds with removed BIOS battery. I am really desperate, I don't know what to do. I know that this passwords are stored in NVRAM and not in CMOS. Is there any other way to reset NVRAM? Any help will be appreciated. Thanks.