How do you reset BIOS and NVRAM on Dell Precision M6600?

How to perform a BIOS or CMOS reset and clear NVRAM on Dell computers.  Scroll down for related articles.

https://www.dell.com/support/kbdoc/en-us/000124377/how-to-perform-a-bios-or-cmos-reset-and-clear-the-nvram-on-dell-systems

Thanks Chino de Oro for the reply, but it seems the Dell Precision M6600 does not apply to any of the suggestions of the CMOS battery, the jumper, or the RTC. I have tried all of those before I posted here, but I will go back and try and again.

Trying again, here is what I get...

Removing the battery, the CMOS battery, AC power, and holding power button for 30 seconds does not clear the BIOS/NVRAM.

Removing the battery, the CMOS battery, and then holding the power button while connecting it to AC power seems to wait for 30 seconds before powering on regardless of how long you hold the power button. The system will get stuck at the Dell Logo loading again. You can let off and then press and hold the power again and it will turn off after 10 seconds without doing anything else until you let off and hit the power button again regardless how long you held it to turn it off. 

Removing the battery, the CMOS battery, connect AC power, and then press and holding the power button while to wait for 30 seconds before powering on regardless of how long you hold the power button. The system will power on after about 10 seconds and then get stuck at the Dell Logo loading screen again and will not do anything else regardless of how long you hold the power button. 

Removing the battery, the CMOS battery, connect AC Power and not pressing and letting the system go through its regular procedure after being plugged in. The system will go through its check and then power itself on after about 10 seconds. 

If the system is stuck in BIOS recovery mode, it would not reset.  Were you able to access one time boot menu for diagnostics or accessing BIOS settings?
  

I have not been able to get into BIOS recovery mode. I have tried holding the CTL + ESC and then adding AC power. If I let go of CTL + ESC when the keyboard lights up, the system will light up power and keyboard and the turn off, light up again and then go to the BIOS Loading screen and get stuck again. 

It will not go past to give you the boot option menu to select diagnostics or settings.

Hitting F2 when powering on gets the message "Preparing to enter Setup..." or F12 gets the message "Preparing ont-time boot menu..." with both getting stuck. The only thing that it does from either selection is the two fans will spin up for a minute or so and then turn off for about a minute or so repeating.

Remove boot drive and/or CMOS battery to trigger error at boot and given access menu.  This model does not support BIOS recovery with USB.  Therefore, see if you can flash BIOS using F12 one time boot menu.