Fix for Explorer.exe crashes on Windows 8.1 Preview due to dlnashext.dll

After installing Windows 8.1 Preview (codename Blue) on my laptop recently I began to notice that every time I opened File Explorer (or Windows Explorer, not IE) it would immediately crash and restart. This would happen if I hit WindowsKey+E or clicked the Explorer icon on the task bar. (For the record, I’m using Windows 8.1 Pro Preview Build 9431)

If I opened File Explorer by using WindowsKey+R (for Run) and typing something like C: and hitting enter, Explorer would open fine. However, once I clicked This PC (Microsoft has renamed “My Computer” to “This PC”. Don’t ask me why there’s no good reason that I’m aware of) it would immediately crash again. It would also crash if I right-clicked on any file on the desktop or within a working instance of Explorer. VERY frustrating indeed!

Further research in the Windows Application Event log revealed the following:

Log Name:      Application
Source: Application Error
Date: 6/29/2013 12:39:28 PM

Event ID:      1000

Task Category: (100)

Level:         Error

Keywords:      Classic

User:          N/A

Computer:      REDACTED


Faulting application name: explorer.exe, version: 6.3.9431.0, time stamp: 0x51bce434

Faulting module name: dlnashext.dll, version: 12.0.9431.0, time stamp: 0x51bcfb3d

Exception code: 0xc0000005

Fault offset: 0x000000000000d56c

Faulting process id: 0xf64

Faulting application start time: 0x01ce750054969779

Faulting application path: C:WINDOWSexplorer.exe

Faulting module path: C:WindowsSystem32dlnashext.dll

Report Id: 9be2167f-e0f3-11e2-9b17-2016d891de48

Faulting package full name: 

Faulting package-relative application ID: 

I began researching this error on the internet and came across this forum posting in the Microsoft Windows 8.1 Preview forum.

Following the instructions for disabling the network adapter did seem to resolve the issue but that presents its own new problems of course.

I resolved the issue by following the instructions in KB article 971760 through Step 2 to get to a Command Prompt. The article is written for restoring Windows 7 but the steps will apply for Windows 8.

Once I had a command prompt open, I then renamed the c:windowssystem32dlnashext.dll file to dlnashext.dll.bak.

I then copied the previous version of the file from before I installed Windows 8.1 Preview from the Windows.old folder (c:windows.oldwindowssystem32dlnashext.dll) to the new Windows installation folder (c:windowssystem32) and rebooted.

I no longer have explorer.exe crashes. There doesn’t appear to have been any ill effects from this change other than some of my icons on the Start screen got re-arranged.


Change DirSync Synchronization Frequency

Some organizations need DirSync to synchronize with their Office 365 tenant more frequently than the default 3 hour interval.

Fortunately, this is easy enough to change.

  1. Navigate to the installation directory for the DirSync tool:
    C:Program FilesWindows Azure Active Directory Sync
  2. Edit this file:
  3. Search for the line
    <add key=”SyncTimeInterval” value=”3:0:0″ />
  4. Change the value to reflect the interval you’d like to use.  The default is 3:0:0 which is every 3 hours.  Changing it to 0:30:0 would result in a synchronization every 30 minutes.
  5. Save the file
  6. Restart the Forefront Identity Manager Synchronization Service service.

DirSync Now Supports Password Sync

Details here.

​This is great news for new and existing users of Azure Active Directory Authentication including Office 365, InTune, CRM Online, etc.

This feature simulates Single Sign-On by copying the hash data for user passwords from on-premises Active Directory Domain Services Domain Controllers into the Azure Active Directory Authentication Service. It also updates password data into Azure more frequently than it does other metadata such as DisplayName, etc. DirSync will detect when a user changes their password and attempt to synchronize it within minutes.

If you’re running the legacy 32-bit version of DirSync, you must first uninstall the older version, and then install the newer 64-bit version on a differen computer.

Download and Installation Instructions.