Both tasks are probably not the culprit, as they do not run at scheduled times. You can verify it by disabling both and reboot. Your machine runs with following features disabled (AFAICS):
- MsCtfMonitor: No keyboard language switcher ("Gebietsschemaleiste" en sp?), no extended languages (like Chinese), probably touchscreen keyboards are disabled with this, too. (You can disable this if you only use American keyboard layout without bad sideffects.)
- SystemSoundService: (AFAICS) Your System is mute and makes no more noises.
If any of these shuts down your system this would be very unusual.
cmd.exe in administrator mode.
schtasks /query >c:\tasks.txt
c:\tasks.txt with your favorite text editor. Skim trhough this list. You will see many blocks like following (Sorry, I am German):
Aufgabenname Nächste Laufzeit Status
======================================== ====================== ===============
RegIdleBackup 30.03.2014 00:04:27 Bereit
(Note that this example is usually not a problem. AFAICS this task backups your registry in case the master is destroyed due to a catastrophic power outage.)
The first line tells you, where you can find the task in
MSC. The second column in the other line probably shows, when the task will be started. Perhaps you can spot it there already.
Now with this overview of tasks handy, you can easily navigate in
MSC. (Without such a map you get easily lost and might miss the culprit.)
- On the left pane select the "Folder" (first line in example above).
- In the middle top pane select the scheduled task in question.
- In the middle bottom pane, look into "Trigger"
- There you usually see when the task is scheduled.
If you cannot spot it in the list from
schtasks you have to look through all the not disabled tasks in the list. Sorry, I do not know a better way.
If you cannot find anything there, you can try to disable all tasks you think you do not need.
You can try look into the event viewer, as noted by Sean. But this might involve enabling event logging of scheduled tasks. Sorry, I cannot explain how to do that if it is turned off (all machines I have access to have event logging disabled, so I think, that may be the same at others).
If this does not help, there are many other sources possible. This is too much to speculate.
Try to change your time on your computer. Does the thing depend on your local system clock? In that case it is local. If not, it is remote.
Another computer can have a scheduled task which shuts down your computer. Disconnect all network interfaces, and look if the effect still hits.
Your BIOS can have a scheduled alarm which powers down the computer. BIOS code can run outside of operating systems, so this affects the computer even if it is not booted into windows.
You can have a bad sideffect of something else running at that time. For example, I had the problem of a computer which started to shut down after logging into one of the local accounts. The problem was a bluescreen due to a corrupt
user.dat which cut the power as well (no, that is not normal behavior), so the bluescreen was shown just a fraction of a second before the computer went black.