At times, for instance after running a resource-intensive program, my normally quite stable Windows7 PC becomes virtually unresponsive for as long as a couple of minutes. Even changing directory in Explorer can show the green progress bar for several seconds, clicking a tab in Chrome causes it to detach in a separate window for 10s, etc.
During this, the CPU usage is virtually zero, nothing is taking more than 1% CPU in TaskManager and the total CPU is often only 2% or so.
Over time, things slowly "heal" to the normal state of responsiveness but computers don't need to heal themselves after working hard!
What problem is this indicative of and what can I do about it? I am running MSE virus-scanner but that's about it for real-time protection.