rounding error when running prime

hi, i was testing my laptop since i have been having windows failed to start problems randomly. it fails about once every 10 starts on average. its a dv6-6b19wm with i3-2330m, intel 3000 graphics, 16gb ddr3-1333 pc3-10600 centon 2x8 modules. 120 gb patriot pyro se with latest firmware. windows 7 home premium with all available updates, all drivers are updated as well. Bios NOT modded so ram NOT overclocked. my laptop runs at about 1.5 gb of ram used at idle so i ran prime95 blend with custom ram usage of 14.5 gb. which i wanted to add up to almost 100% used. i got an fatal rounding error on worker #4 almost instantly. ram usage was at 15.95gb with prime running. i have clean mem running at the bottom corner of desktop, i also have cpu meter running too. so thats how i knew of my ram usage. was my error caused because I took it to almost 100%? should i leave some unused? Could the ram be failing? it has a lifetime warranty. now i get a different error code on worker #4 and it wont start now ill put screenshot up so you can see it. any insight would be great. thanks.

ok, when i run prime in small fft all workers run and its still running but dosent test ram much. thanks

now im running blend but i took ram usege down to 13.5gb for a total of 14.7gb or 93% here is a screenshot of that. i think the error was because i tried to use more than 16gb of ram but im not an expert.