Hi,
I have the same problem on both of my PCs (Notebook aud Desktop).
What I've found out so far:
-Several Users reported a broken Task scheduler in Windows 7 in combination with ccleaner.
-Apperantly, the task scheduler cache gest broken.
-The tasks themselves are still present in \windows\system32\tasks\... (please check)
-Task scheduler cache can be repaired by deleting all entries under the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache
and restarting. After that, the schedulder seems to run without errors, BUT it still cannot display all old tasks. At least, you can make you own tasks again. You will still get errors, when the system wants to change its own tasks (e.g. when activating/deactivating system restore).
-Obvieously, Some other part of the task scheduler database seems still to be broken.
-If nobody reports more on this topic, I will test ccleaner on a fresh Win7 install and check, which option breaks the scheduler.
Greetings,
IF