Windows 8 Unexpectedly Closes Explorer Windows

by Ed Sparks

A strange quirk noted at several customer sites recently - and apparently fairly widely reported - is users with Windows 8.1 or 10 experiencing their File Explorer windows disappearing in the middle of using their system.

The cause is due to newly introduced behaviour in Group Policy Preferences (GPP)  for Drive Mappings.  Prior to Windows 8.1, GPP Drive Mappings would only get added or updated at logon.  Now, the preferences will apply whenever the Group Policy Background Refresh cycle occurs.

A side effect of this new behaviour is that any Drive Mappings that are configured with an action of Delete or Replace will cause File Explorer to disconnect the drive (and thus handles to any open files!) and then recreate the drive mapping.  While it does this, it kills the actual opened window for any folders on that drive.  It happens quickly, so many users don't notice any other symptoms except their File Explorer windows disappearing, along with occasional inability in open files.

While it's understandable why Microsoft implemented this improvement to allow on-the-fly changes to Drive Mappings, this is poor default behaviour and not obvious to users.  Even a warning popup would be nice.

The trick to resolve? Make sure the only action for GPP Drive Mappings you use is Update.  The good news is this action works in almost all scenarios, including if a user were to map the same drive letter to some other resource themselves (while at home, for example). In this instance, the GPP will override their mapping.  Update also creates a new mapping if it doesn't exist before (which isn't clear from the name 'update')

Of note, this issue obviously only affects corporate users, as home users don't normally use Group Policy.  If you're seeing this on a non-domain machine, let us know in the comments.

Side Note:  Love the 1990s era WIndows XP UI that still exists in Group Policy, Microsoft


Fix Event 513 CAPI2 Errors During Windows Backup

by Ed Sparks

Update: March 2016.
Commenters have noted this same fix appears to work correctly on Windows 10 as well

A semi-common error seen on various Windows 8.1 and 2012/R2 systems is the following during the start of system backups that use VSS (i.e. most backups).  This often causes the backup process to hang for a long period of time, or fail.

Application Event Log:
Cryptographic Services failed while processing the OnIdentity() call in the System Writer Object.

AddLegacyDriverFiles: Unable to back up image of binary Microsoft Link-Layer Discovery Protocol.

System Error:
Access is denied.

Much digging through forums has found what appears to be the cause.

During backup a VSS process running under NETWORK_SERVICE account calls cryptcatsvc!CSystemWriter::AddLegacyDriverFiles(), which enumerates all the drivers records in Service Control Manager database and tries opening each one of them. , The function fails on MSLLDP record with "Access Denied" error.

Turned out it fails because MSLLDP driver's security permissions do not allow NETWORK_SERVICE to access the driver record.

What causes this to have incorrect permissions in the first place is unclear, but a fairly simple fix exists.  We've tested this on several systems without issue, but your mileage may vary.

It can be fixed by correcting the Security Description on the MSLLDP service, using the built-in command line utility SC.exe

Open an Administrative Command Prompt (NOT PowerShell) and execute the following.  This must all be one long command without carriage returns


You should receive a successful result of

[SC] SetServiceObjectSecurity SUCCESS

If so, the problem is resolved, and there's no reboot required.  The next backup should complete successfully.

Windows 8.1 Looks Promising (ish)!

by Ed Sparks

We've been playing with the Windows 8.1 Preview Release for a few weeks, and it looks like a strong upgrade that mostly cleans up the half-baked feel of Windows 8. 

The whole thing feels more polished and refined, and even in this preview stage they're clearly hitting the mark and making it a more useful and livable OS regardless if you choose the Modern or "traditional" Desktop world.  It's just some compromise, instead of all compromise. Windows Server 2012 R2 looks just as good, though honestly guys just scrap Metro on this thing.  Please.  Seriously.  NOBODY wants this.

Let's hope they get this right, as it would be great to have this OS we know (and love?) succeed into the next generation.  This at least gives us hope, especially if they can get Surface 2.0 devices right too.

A Few Quirks 
We are seeing a few glitches, though this is to be expected with a beta - err - preview release. 

Skydrive is now fully integrated (and properly!) into the OS both on the Desktop and Metro side. There's nothing extra to install and your cloud storage shows up just as if it were local. However, it doesn't sync everything by default anymore.  In fact, the exact opposite - everything is cloud first, which makes a lot of sense.  
The problem?  On many of our upgraded test systems it doesn't sync anything at all, due to some glitchy upgrade code.  This seems to be the result of broken interaction between the former standalone desktop Skydrive client, and the new built-in version.

The Fixes

  1. Make sure you have no junction/mount points defined anywhere in your old Skydrive path (c:\users\<username>\skydrive usually).  These immediately break things, though they were never really supported.
  2. Check Task Manager to make sure the skydrive.exe executable is not running, then open up %localappdata%\Microsoft\Windows\Skydrive.  Delete all the contents of this folder, then from a Run dialog, type 'skydrive.exe' and click OK.  Again check if skydrive.exe is running in Task Manager and that everything is now syncing.

The other big problem we're seeing?  It's unstable - very!.  So far it crashes at least once a day.  We're talking hard system reboot crashes (though oddly not blue screens).  So far it seems video driver related.  Fingers crossed that's just an early preview glitch.

The good news is Microsoft seems to be aggressively updating this through Windows Update, and often!

Wish List

  1. Notification Centre.  It's beyond annoying that alerts popup everywhere for just a few seconds, that can then never be found again.  The Start Screen Live Tiles don't help, as they only show a tiny bit of what's going on, and offer no deep-linking support (i.e. if I click a Start Screen icon with information showing, I'm not actually taken to that information - just the app in general, which is stupid).  Come on - you even have a button called "Notifications" in the Settings Bar.  How about clicking that brings up all the notifications? Just a thought guys!
  2. System-wide media controls.  Snapping any media-related app just so one can pause, skip or change the volume is stupid.  Android and iOS handle this WAY better. Just make this part of the (still ridiculously named) Charms Bar.  It's got loads of wasted space.