I noticed that the scheduled tasks for disk defragmentation and Windows Defender scanning do not run on my computer under Windows 7. Even though the tasks are due to run on a set schedule, when the time arrives for them to run, they do not trigger. These are the preinstalled tasks, I have not done anything to change them. I have not turned off any services, the only thing I have done since installing Windows 7 is to turn off system restore. As an experiment I tried making a new scheduled task to defragment the disk but it also did not seem to trigger. However looking at some of the other scheduled tasks I can see that some of them do seem to run, however when I look at the disk defrag task and the Windows Defender task, under the "last run time" column they both say "never". The "next run time" for the tasks does show the correct scheduled time, but when the time arrives the tasks do not run, and it just updates to show the next scheduled time. I wonder if anyone knows of anything which might be causing these tasks not to run?

Just a shot in the dark here, but do you have a password on your account? Windows XP and Vista had issues like this that occurred when a blank password was used.- John

no i don't use a password. i will try setting a password and see if it helps, thanks.

Check to make sure that your Windows Event Log service is running properly. Not just the service itself, you have to go into the Event Viewer and maker sure you are not getting error popups when looking in the different sections. The Task Scheduler is heavily dependant on that service for proper functioning. GA P35 DQ6 Mb, Intel Wolfdale 8600 3.33Ghz C2D CPU., 4x2Gb Mushkin DDR2 1066 PC2 8500 Ascents Memory Mods., PNY-nVidia GE Force 8800 GTS (640MB), 4-Western Digital Caviar SATA(2) HDD's (internal), 1 EIDE-USB External; Hauppauge PVR 1600 TV tuner, Dual Monitor: (1) Standard up top, (1) WideScreen below; Altec Lansing Speakers. Here Kitty, Kitty...that's my Kitty Kat, he's a Kat, because he is kat...kat.

Hi,Both of these tasks depend on the computerbeing idle for a period of time before they run. The default for Defrag is 3 minutes. There is no time specified forWindows Defender. I had to uncheck the box that said "run only when system isidle" for Defender but defrag seems to work okay as long as the computer is idle.

Hi, thanks for the suggestions, but I'm still having trouble. The Event Log service is running, the Event Viewer is fully functional, I've set a password for my account, and the Windows Defender task is only set to wait for the computer to be idle for 1 minute before running, which my computer definitely has been several times over the past few days, however the Defender daily scan task still doesn't run. All it seems to do is update the "Next Run Time" according to the schedule, without actually running. It still shows "Never" under "Last Run Time". The Defrag task has changed its status to "Queued" however - does this mean it will eventually run? I left my computer idle for over 3 minutes (which is how long it is set to wait) but it didn't trigger. I do have AVG Antivirus installed which has caused a problem running another program, that is the only other issue I have had, so if I had to guess I might think AVG was causing the problem. I have been able to create my own Defrag task which does run but it would be nice if I could get the default task to work.

I'd suggest removing the AVG to see if that's the issue. Obviously you'll need another antivirus to run in it's place - so be sure to select one that works with Windows7. I use Avira Free on my 32 bit Win7 tablet, and Avast Free on my 64 bit Win7 desktop.- John

OK, I've switched to using Avast, but this morning when I checked Task Scheduler, the Windows Defender task still shows "Never" under Last Run Time, but the Next Run Time has already updated to tomorrow, meaning it must have skipped running today. Another odd thing I've noticed is that when it updates the Next Run Time it changes the time it is set to run. Originally it was scheduled to run at just before 2am, then it changed to 3am, then 4am, and at the moment it is scheduled to run at 5:58am, even though I haven't changed anything... Weird. Also, yesterday, the Defrag task which was queued eventually did run, but the result was "0x42B", which searching Google suggests means "Error Process Aborted".

hinksy,Do you have the 'All Tasks History' turned on? I finally found this task listed as 'MP Scheduled scan', and it says 'Last Run Time' is Never... However when I check through the task history tab, I find that it was completed daily, just like it is supposed to. Once the task has completed, it has a message saying 'Task registration deleted' and then 'Task registered' right after that. Since it is deleting the task and re-adding it after completion, we are seeing 'Never' as the last time run.

No, the history is disabled in Task Scheduler, I will try turning it on. However, it is not just Task Scheduler that says scans are not taking place - when I run Windows Defender it shows in its status box that the computer has not been scanned for over a week. If daily scans were in fact taking place shouldn't Windows Defender know about them without needing the Task Scheduler history enabled? And if not, shouldn't the history be enabled by default? Anyway I will turn the history on and see what happens, thanks.

OK I've turned the history on, and as you suggested the Windows Defender task is being deleted and recreated... but it is never running. The history just shows three events each time the task is due to run, it shows "Task registration deleted", followed by "Task registered" followed by "Task registration updated", all taking place within one second. But that is all that is happening every day, in fact this is happening twice every day. But there are no entries at all in the history saying anything like "Task Started" or "Task Completed", just those three same messages about deleting and registering and updating the task. This strikes me as being a bit strange...