Runtime Broker is using too much memory.
Runtime Broker is a Windows process in Task Manager that helps manage permissions on your PC for apps from Windows Store.
It should only use a few megabytes of memory, but in some cases, a faulty app might cause Runtime Broker to use up to a gigabyte of RAM or more. If your RAM use is high and your PC is running slowly, an app may be the cause of the problem. To stop Runtime Broker, use the software KillRB.