We keep getting this stop screen that tells you to disable the BIOS memory options such as caching and shadowing. 1) How do you do this? 2)What causes this to happen? 3) How can I prevent it in the future? We also get error messages about video drivers and RAM errors...

I think your talking about the Blue Screen Of Death? Short-form: BSOD. It is a Windows thing, not Dell, and it can be caused by all kinds of problems.

Was the PC running smoothly before? Did you install some new program(s)? Is this Dell a recent purchase? Please provide some details.

You can open the PC, and ensure that all parts are tightly inserted , fitted well, not loosen, etc.

Dell BIOS normally uses F2 to enter, and its call Setup, as soon as your turn on the PC, quickly press F2 to get into the BIOS setup screen. Here you can enable, disable many hardware settings, so look for the cache and shadowing options and disable it.