It is hard to tell if it is caused by a virus or what -I do have Avast AV system - but since moving from 4.10 to 4.12 my cpu usage has increased astronomically to the rate that virtually nothing works , or takes an inordinate amount of time to call up and run programs.
Even with nothing else working cpu usage is 100% - there are and always have been a lot of programs resident in the system tray - but 4.10 did not affect the cpu useage like this one.
When I upgraded to 4.12 - had this problem - uninstalled and system was fine
Re-installed and it woked okay for 2 days and now we are back to whistling while programs are working between keystrokes.

What to do?