May be hidden. You have to change that option in Folder options > Show Hidden Files or Folders.

http://www.bleepingcomputer.com/tutorials/how-to-see-hidden-files-in-windows/#windows8

No idea about the schedule scan. I do not run win 8. However I understand, it has a funny hybrid go to sleep and restart fast mode. So… you can start there, see if that interfere with schedule task for any program.

Good place to ask: http://www.eightforums.com/