A little more context here would help a lot in how specific we can get with a response. What are you specs (CPU/GPU) and is there something specific you're doing while this happens? Maybe opening a browser or perhaps watching a video, anything that could possibly spike your resource use? With a little more info we can better provide a possible solution.
ryzen 7 5800x 6700xt 32gb ram doubt the computer the issue. not much to say it just keeps closing for no reason. runs fine for hours and then start crashing, restart computer uninstall reinstall. nothing ive seen recommended seems to help.
QuayleMan
Yeah you definitely have sufficient specs, my only guess is could be a driver issue as I have heard of people with AMD builds running into stability issues with RuneScape. Only suggestion I know of is trying a different version of your driver and see if that fixes it. Sorry!