An old scuggie, with Win 8, fell for the "I am from Telstra, and your computer is infected" trick, it's easy to be swayed by their arguments don't worry.
They're sneaky as they do the trick of on the pretence of helping you, take over your computer, and then they put on a software program where the trial period has supposedly expired and it demands purchase to get a code to open it.
The program on this scam was Classical Menu 8, so whenever you tried to go anywhere, the screen was virtually covered by a window that stops you accessing your menus and there appears nothing you could do but purchase the item. It jammed any access to the side panel to access the Control, Panel
or the task bar or the Jewel. The Windows flag also didn't work.
The free version of the uninstall program Revo Uninstaller you was the solution, fortunately the Task manager Ctrl-Alt-Del still worked and I could stop the demanding Classic Menu obstruction in the processes tab and then check in the services tab and disable any mentions of classic menu, there were 2 entries. I also removed it from the Start menu.
That stopped it popping up and then I downloaded the Free version and then ran Revo and searched through its list of programs to uninstall and let it to do it's magic and winkle out all the entries, after deleting these after restarting the laptop it did not pop up the demand. Phew. You do have to be a bit of a tiger with this.
So it's not that sophisticated, and I suppose I do have a pretty good idea of what is listed in the processes even if I don't know what they are. So it is worth you looking there every now and again and try to get an overall view of what is listed, unusual programs can stand out sometimes.
Sometimes you can win...