How to cancel a schedule scan in progress?

Following on from previous question about the behaviour of missed scans, assuming we are not using any passwords on avast, how can the user (who is a local admin) cancel a running scan. The UI doesn’t appear to show the scan running, but the avast scan task is using up 50% CPU and the hard disk is being hammered, so I assume it is scanning. The BPP Console however doesn’t show anything - just that 4 computers could not be contacted when the quick scan was done.

How can we cancel a running scan please- the CEO wants to get back to work. Thanks