KB841873, the fix applied via Windows Update recently as a result of Microsoft Security Bulletin MS04-022, has been shown to cause Windows Task Scheduler to cease functioning on some computers.
If you rely on Windows Task Scheduler to perform backups, or other critical operations, and you have recently updated your computer with the critical fixes provided by Microsoft, I recommend that you check to see if you task scheduler jobs have actually been running. If any of the entries have a status of “Could not start” – then you might have this problem (or you’ve just not configured task scheduler correctly!)
The fix I found was to uninstall KB841873, followed by resetting the “run as” password for every entry in task scheduler.
Note that this problem has been shown to occur on some Windows 2000 and Windows XP machines where the patch has been loaded. I have one WinXP machine which had the problem, and I have another two WinXP machines which did NOT have the problem. I have also verified with other people running Win2K that this problem exists on some of their patched machines too. It may also occur on other versions of Windows, but I have not yet verified this.
I will be keeping an eye out for information from Microsoft about this problem – hopefully they will release a fix for this fix.
I only discovered this problem last night after noticing that another task hadn’t run. It turns out it hadn’t been running all week, and neither had my backups of this blog or any of my other sites and forums, which are run from my machine using task scheduler ! That could have been catastrophic !!
Shahid says
The way I got it to work was:
1) I created a local account on my machine.
2) put in administrator’s group.
3) in local security policy (under administrative tools) gave the rights of “log on as a service” and act as part of operating system. After that it should work
Dolores Jandik says
Yes, I had the same problem after applying that security update. It breaks the task scheduler. However I am surprised that not too many people have posted complaints about it.
Dolores Jandik says
This week we got three new windows xp pro machines with spk1a on them and after applying a set of security patches to it the task scheduler will fail with error messages toggling between complaints about the password or about the task being scheduled. After removing one patch at a time I found out the patch KB841873 was the one to be blamed. I went to the patch technical details and sure enough, the patch was supposed to fix a vulnerability in this item.