So this problem has been bothering me for months and being the busy guy I am, I’ve ignored it as it was a small annoyance until this weekend. In the morning, I’d put my computer to sleep, then when I’d come home my computer would be on. Some would ask what’s the problem with that? Well the problem is that I set no wake-up timers and wake-on-LAN is turned off. So when the power went out while my computer was updating itself because it decided to turn itself back on while I was away…it forced me to do a restore from my Windows Home Server. Thankfully the WHS backup worked great.
So I set out on hunting down the problem and I’ve compiled all the helpful hints and processes I’ve found for tracking down why your computer is turning itself back on.
My problem specifically stemmed from that I have Windows 7’s Media Center installed, setup and with the guide updates turned on.
Some general maintenance should always be done first to avoid getting to far into the problem and realizing your computer just needed an update.
1. Update your computer with Windows Update (Windows Vista and Windows 7 users just go to the Start Menu and type in the search area “Windows Update” without the quotes to get them started).
2. Go to your computer’s website and download the latest BIOS update. Refer to the manufacturer’s instructions and update your BIOS via it.
Next, if you’re still having problems, it’s time to start troubleshooting. You can find which devices are set to be allowed to wake up your computer by running the following command in the command prompt: powercfg –devicequery wake_armed . If you see something in there out of the ordinary, or that makes you palm –> face then you’ve probably found the culprit and can GOTO 10: rejoice AFTER turning off the device’s ability to wake the computer by performing the following: in device manager, right-click the device listed in Step 2 and select Properties, switch to Power Management tab and clear the checkbox of Allow this device to wake the computer.
Now for me, none of these got me to the solution because it was Media Center’s scheduled update task that was causing the problem, not hardware. So if you find yourself sifting through devices that all seem to be ok, then you should continue on like me and check your Event Viewer (a quick shortcut to the Event Viewer is to go to Start –> Run then type eventvwr.msc and hit enter).
Now look through the System log first, and the Application log second as that should be the proper order of probability. If you find that your computer seems to be waking up at say 4:17pm everyday like mine, then look for events around that time, usually right next to the first event at that time, that could be a culprit like a scheduled task.
I found event stating that mcupdate_scheduled had requested to wake the computer. It looked like this:
Event Source: power-troubleshooter
The system has resumed from sleep.
Sleep Time: 2009-11-07T17:01:22.662051300Z
Wake Time: 2009-11-07T22:14:14.102034400Z
Wake Source: Timer – Windows will execute ‘\Microsoft\Windows\Media Center\mcupdate_scheduled’ scheduled task that requested waking the computer.
Since it was listed as a scheduled task in the Event Viewer, then I knew to continue on to the Task Scheduler to remove or change that task’s properties (a quick shortcut to the Task Scheduler is to go to Start –> Run then type taskschd.msc and hit enter). From the Task Scheduler you can either search for the task name, or browse down through the hierarchical menus. The path through the menus is given to you from the item found in the Event Viewer. Thus I navigated down the folders from Microsoft –> Windows –> Media Center and then found the mcupdate_scheduled task. From here you can delete the task or modify it’s properties, like I did, to simply not allow the task to wake the computer to perform the task. Voila!
As always, feel free to comment if you need help with a similar issue!