dismhost.exe recreating itself every few minutes in C:\Windows\Temp, each time contained in a different folder GUID name (e.g. AE7D13F2-AA05-4FEC-B7F2-C633CB049B52), so that my Temp folder is massively filled up with these folders with different GUIDs - each of which contain the very same DismHost.exe and 23 other files. The task manager currently shows three instances of dismhost.exe, each running from its folder it was created in.

If I look at the date created / date modified times of those folders I see them being recreated every 5 minutes. I realize this might have to do with scheduled tasks. Looking at the Event viewer's TaskSchedulerOperational log, I see that each time the folder is created, a few corresponding tasks are completed involving:

 

(6:17:36 PM) User "NT AUTHORITY\System"  deleted Task Scheduler task "\Microsoft\Windows\RemovalTools\MRT_HB"
(6:17:36 PM) Task Scheduler terminated "{cec331bf-600b-4dc1-a04a-0cdac76eb224}"  instance of the "\Microsoft\Windows\RemovalTools\MRT_HB"  task.
(6:17:36 PM) User "WORKGROUP\USER$"  updated Task Scheduler task "\Microsoft\Windows\RemovalTools\MRT_HB".
(6:17:36 PM) User "WORKGROUP\USER$"  registered Task Scheduler task "\Microsoft\Windows\RemovalTools\MRT_HB"
(6:17:42 PM) Task Scheduler stopped instance "{a8f205a7-2a2b-4279-be9c-f2a05bd3c788}"  of task "\Microsoft\Windows\TaskScheduler\Idle Maintenance"  because computer is no longer idle.
(6:17:42 PM) Task Scheduler stopped instance "{6ef6a8d8-78e5-49ed-ba4a-0fffd01134d0}"  of task "\Microsoft\Windows\MemoryDiagnostic\RunFullMemoryDiagnostic"  because computer is no longer idle.
(6:17:42 PM) Task Scheduler successfully finished "{ec0e75e5-9dc5-4d8e-a8ff-8514d97f13f5}" instance of the "\Microsoft\Windows\Windows Defender\Windows Defender Verification" task for user "NT AUTHORITY\SYSTEM".
(6:17:42 PM) Task Scheduler terminated "{ec0e75e5-9dc5-4d8e-a8ff-8514d97f13f5}"  instance of the "\Microsoft\Windows\Windows Defender\Windows Defender Verification"  task.
(6:17:42 PM) Task Scheduler stopped instance "{ec0e75e5-9dc5-4d8e-a8ff-8514d97f13f5}"  of task "\Microsoft\Windows\Windows Defender\Windows Defender Verification"  as request by user "NT AUTHORITY\SYSTEM" .
(6:17:42 PM) Task Scheduler successfully completed task "\Microsoft\Windows\Windows Defender\Windows Defender Verification" , instance "{ec0e75e5-9dc5-4d8e-a8ff-8514d97f13f5}" , action "%ProgramFiles%\Windows Defender\MpCmdRun.exe" with return code 2147942659.
(6:17:42 PM) Task Scheduler successfully finished "{d7087f2b-9d3e-4047-953b-b367258f6367}" instance of the "\Microsoft\Windows\Application Experience\ProgramDataUpdater" task for user "NT AUTHORITY\SYSTEM".
(6:17:42 PM) Task Scheduler terminated "{d7087f2b-9d3e-4047-953b-b367258f6367}"  instance of the "\Microsoft\Windows\Application Experience\ProgramDataUpdater"  task.
(6:17:42 PM) Task Scheduler stopped instance "{d7087f2b-9d3e-4047-953b-b367258f6367}"  of task "\Microsoft\Windows\Application Experience\ProgramDataUpdater"  as request by user "NT AUTHORITY\SYSTEM" .
(6:17:42 PM) Task Scheduler successfully completed task "\Microsoft\Windows\Application Experience\ProgramDataUpdater" , instance "{d7087f2b-9d3e-4047-953b-b367258f6367}" , action "%windir%\system32\rundll32.exe" with return code 2147942659.
(6:17:42 PM) Task Scheduler successfully finished "{2450f1e1-3106-459d-a074-84b0b7843c3a}" instance of the "\Microsoft\Windows\Windows Defender\Windows Defender Scheduled Scan" task for user "NT AUTHORITY\SYSTEM".
(6:17:42 PM) Task Scheduler successfully completed task "\Microsoft\Windows\Windows Defender\Windows Defender Scheduled Scan" , instance "{2450f1e1-3106-459d-a074-84b0b7843c3a}" , action "%ProgramFiles%\Windows Defender\MpCmdRun.exe" with return code 2147942659.
(6:17:42 PM) Task Scheduler stopped instance "{2450f1e1-3106-459d-a074-84b0b7843c3a}"  of task "\Microsoft\Windows\Windows Defender\Windows Defender Scheduled Scan"  as request by user "NT AUTHORITY\SYSTEM" .
(6:17:42 PM) Task Scheduler terminated "{688997da-a1f5-4fbf-8cd6-f950de2162c2}"  instance of the "\Microsoft\Windows\DiskFootprint\Diagnostics"  task.
(6:17:42 PM) Task Scheduler stopped instance "{688997da-a1f5-4fbf-8cd6-f950de2162c2}"  of task "\Microsoft\Windows\DiskFootprint\Diagnostics"  as request by user "NT AUTHORITY\SYSTEM" .
(6:17:42 PM) Task Scheduler terminated "{2450f1e1-3106-459d-a074-84b0b7843c3a}"  instance of the "\Microsoft\Windows\Windows Defender\Windows Defender Scheduled Scan"  task.
(6:17:42 PM) User "WORKGROUP\USER$"  updated Task Scheduler task "\Microsoft\Windows\TaskScheduler\Regular Maintenance"
(6:17:42 PM) Task Scheduler successfully finished "{a8f205a7-2a2b-4279-be9c-f2a05bd3c788}" instance of the "\Microsoft\Windows\TaskScheduler\Idle Maintenance" task for user "NT AUTHORITY\SYSTEM".
(6:17:42 PM) Task Scheduler successfully completed task "\Microsoft\Windows\TaskScheduler\Idle Maintenance" , instance "{a8f205a7-2a2b-4279-be9c-f2a05bd3c788}" , action "Maintenance Launcher Handler" with return code 2147947270.
(6:17:43 PM) Task Scheduler successfully finished "{cec331bf-600b-4dc1-a04a-0cdac76eb224}" instance of the "\Microsoft\Windows\RemovalTools\MRT_HB" task for user "NT AUTHORITY\SYSTEM".
(6:17:43 PM) Task Scheduler successfully completed task "\Microsoft\Windows\RemovalTools\MRT_HB" , instance "{cec331bf-600b-4dc1-a04a-0cdac76eb224}" , action "C:\WINDOWS\system32\MRT.exe" with return code 0.

From those events I conclude the recreation of dismhost.exe folders occurs during Windows maintenance tasks. Anyway to stop them from duplicating and taking up Gigs on my SSD?

Appreciate the help.

• Edited by wonderous Monday, March 30, 2015 1:40 AM

I seemed to have stumbled on a solution myself.

I left my two Windows 8.1 computers (the one with the problem and another without) idle with the Windows Defender window open, and i noticed that whenever Idle maintenance was triggered (about 5 to 10 minutes of idling), Windows Defender window (if open) would show a quick scan taking place on the working PC, but not on the problematic PC.

I suspected the problem seemed to have to do with the 'Windows Defender Scheduled Scan' task not being able to start by 'Idle Maintenance' task. To test this what I did was to open Task Scheduler (Local) and navigate to: Microsoft > Windows > TaskScheduler, and going to properties of 'Idle Maintenance' task under Settings tab I set it to 'Allow task to run on demand', then ran the task. Immediately, if you have Windows Defender window open, a quick scan should have started; this was happening on another working PC, but not on the problematic PC, so next I navigated to Microsoft > Windows > Windows Defender and ran 'Windows Defender Scheduled Scan' on demand; again Windows Defender window should show a quick scan taking place immediately, and this was happening on both PCs.

Somehow one on-demand run of the 'Windows Defender Scheduled Scan' task fixed the "bug" where Idle Maintenance wouldn't run it. To test if it was working i restarted my PCs and left them idle with the Windows Defender window open so I could watch. Successful Windows Defender quick scans are now taking place on my problematic PC. The C:\Windows\Temp folder isn't showing any subsequent creation of DISM GUID folders anymore, since Windows Defender task isn't being "interrupted" or prevented any longer.

As to why such an on-demand running of a Scheduled task could fix a task, I suppose sometimes Scheduled Tasks may fail to work and just needs some kind of re-apply of settings to work again.

• Edited by wonderous 4 hours 24 minutes ago

I seemed to have stumbled on a solution myself.

I left my two Windows 8.1 computers (the one with the problem and another without) idle with the Windows Defender window open, and i noticed that whenever Idle maintenance was triggered (about 5 to 10 minutes of idling), Windows Defender window (if open) would show a quick scan taking place on the working PC, but not on the problematic PC.

I suspected the problem seemed to have to do with the 'Windows Defender Scheduled Scan' task not being able to start by 'Idle Maintenance' task. To test this what I did was to open Task Scheduler (Local) and navigate to: Microsoft > Windows > TaskScheduler, and going to properties of 'Idle Maintenance' task under Settings tab I set it to 'Allow task to run on demand', then ran the task. Immediately, if you have Windows Defender window open, a quick scan should have started; this was happening on another working PC, but not on the problematic PC, so next I navigated to Microsoft > Windows > Windows Defender and ran 'Windows Defender Scheduled Scan' on demand; again Windows Defender window should show a quick scan taking place immediately, and this was happening on both PCs.

Somehow one on-demand run of the 'Windows Defender Scheduled Scan' task fixed the "bug" where Idle Maintenance wouldn't run it. To test if it was working i restarted my PCs and left them idle with the Windows Defender window open so I could watch. Successful Windows Defender quick scans are now taking place on my problematic PC. The C:\Windows\Temp folder isn't showing any subsequent creation of DISM GUID folders anymore, since Windows Defender task isn't being "interrupted" or prevented any longer.

As to why such an on-demand running of a Scheduled task could fix a task, I suppose sometimes Scheduled Tasks may fail to work and just needs some kind of re-apply of settings to work again.

• Edited by wonderous Friday, April 03, 2015 2:55 AM