You can look at clearing your browser cache. Also look at not having a lot of tabs open at one time. Every open tab uses more memory. Chrome is notorious for using a lot of memory. Reboot your computer periodically in order to flush RAM. Sometimes software will not release memory when you close them. Next time it happens look in the Windows Event Viewer application events and see if you see any errors. Google them. Good luck. Computers are of the devil. I've been in IT 20 years I know this first hand.