The way I understand it, the file or folder in system32\tasks is only important if there is an entry in the registry in Taskcache. The only thing that a file without a TaskCache entry will do is keep you from scheduling a new task of the same name.
Where it really gets upset is when it has an entry in the TaskCache and no file or folder in System32\tasks.
Let's try deleting the following tasks which do not have files (in some cases the folder is also missing) .
Task Scheduler, Task Scheduler Library in the right pane find:
29B60F45-78D0-4DF7-9E16-888CE01E439C or PCDEventLauncher
Right click on it and DELETE
repeat for:
{7045A06E-965A-402F-9A76-29866C6ADF36} or CreateChoiceProcessTask
{5C367FF4-CFEF-47B4-8463-C7AC04BE1C5A} or avast! Emergency Update
Look in Microsoft, Windows Live, SOXE or maybe it's just Windows Live, SOXE and delete this one:
{B6899CF2-5B30-4602-9D85-39E4031B0E3B} or Extractor Definitions Update Task
Look in Windows, Media Center and right click and disable everything in that and the subfolder Extender. For some reason you only have two files available so best to just disable all of them.
Reboot and check to see if that helped. If not run the same
reg query "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule" /s > \junk.txt
dir /a /s \windows\system32\tasks >> \junk.txt
dir /a /s \windows\tasks >> \junk.txt
notepad \junk.txt
as before and attach it.