My computer keeps telling me I'm low on memory, which is ridiculous. How can I make it stop?

I should preface this by saying that, yes, I have Googled for help, but I’m not the most computer-literate and get really frustrated when trying to read through message boards and the like. If someone can explain how to fix my problem quickly and painlessly, I’d be forever grateful!

I’m running Windows 8.1 64-bit, and I have a 2.5G processor. I have eight freakin’ gigs of RAM and a terabyte of memory, so there’s no way I’m actually running low on memory.
I read somewhere that there’s a way to change the amount of memory being used so that I won’t be getting those annoying error messages and my computer won’t shut itself down, but I have no idea how to do it. Help, techies?