I had a desktop PC dropped off today because it was running to slow to use. The owner said the PC was being used by one of her sons who had started to complain saying that he wanted a new laptop for Christmas as his old desktop was too slow to use for school work.
It took an age to fire up to the desktop and just “hung” for 5 minutes. Once I had gained control I noticed that the PC had TWO well known free anti virus products installed.
I uninstalled one of them , rebooted and the desktop was as good as new, just a few software upgrades and a quick virus and malware scan and the PC was on the way back home to happy mother … but probably a disappointed teenager this Christmas !