So, I wanted to report back my findings on this.


It seems that my issues may be related to asynchronous running of the GPO,
logon scripts and the system starting. I have found that the drives that
aren't seen in Explorer (but are at the command prompt) ARE seen if I were
to run another application, lets say Word. Also, if I were to restart the
Explorer process they show right back up and are accessible.


I was able to (seemingly) fix the problem by setting the local computer
policy of CC>Administrative Templates>System>Logon>Always wait for the
network at computer startup and logon to enabled. With this setting on it
takes a little bit longer to log in, but when the logon happens the drives
are all there and visible. I haven't been able to repeat my issue after
doing this.


This works OK for this desktop system I'm working with. It'll be a
stationary machine and will always be plugged into a wired connection. This
won't solve the issues for other machines on my network, though, as I cannot
push this policy through my GPO because of the mobile workstations we have.
I tested it on a laptop with the network turned off and the machine would
not login, even using cached credentials.


So, I seemed to have solved my current issue with this, but I foresee other
issues down the road unless I can think of other ways to mitigate the



From: Technology Discussion at UVM [mailto:[log in to unmask]] On
Behalf Of Mickey Mossey
Sent: Tuesday, October 13, 2015 11:47 AM
To: [log in to unmask]
Subject: Re: Odd GPO Mapped Drives issue in Windows 10


Nothing that's consistent.


For instance, I just logged in as me on the machine I'm building. This time
our "N: drive" mapping didn't appear and isn't usable in explorer, but is
accessible via the command prompt. It also took a few minutes for the drives
to show up. There is nothing more than the informational entries in the
Group Policy logs.


Sometimes, though, I get the warnings or errors that say something to the
effect of "Completed Group Policy Drive Maps Extension Processing in 151735
milliseconds" (actual entry & processing time). BUT, that never necessarily
corresponds with having these issues. I went probably went a good half dozen
logins before I saw the issue repeat.


This is happening with two separate GPOs, too. My main work machine uses a
special GPO for our IT group and the peripheral machine I'm working on is
using our general user GPO.


Mickey Mossey


From: Technology Discussion at UVM [mailto:[log in to unmask]] On
Behalf Of Geoffrey Duke
Sent: Tuesday, October 13, 2015 11:31 AM
To: [log in to unmask] <mailto:[log in to unmask]> 
Subject: Re: Odd GPO Mapped Drives issue in Windows 10


Mickey, this is a very curious behavior. Is there anything in the event logs
that corresponds to the time that your drive-mapping process runs? If it's
straight-up Group Policy Preferences, there should be events logged when
they happen.




From: Technology Discussion at UVM [mailto:[log in to unmask]] On
Behalf Of Mickey Mossey
Sent: Monday, October 12, 2015 11:42 AM
To: [log in to unmask] <mailto:[log in to unmask]> 
Subject: Odd GPO Mapped Drives issue in Windows 10


So, here's something super odd. I have been using Group Policy Objects to
map drives on our systems now for years. These policies have been set up and
they work absolutely fine in my environment which is 99%+ Windows 7
currently. I have been running Windows 10 since the first day it was
available to us here, because you know, I'm brave. I had seen throughout the
last three or so months on my system that occasionally out of nowhere, I'd
completely lose a mapped drive. When I'd pull up an application I wrote that
helps my users map drives while remotely, the tool would actually report the
drive was already mapped - even though it wasn't in Windows at all.
Occasionally toggling the drive off and then back on would bring it back,
other times I'd need to reboot my computer to get it back. Then, it'd
disappear again down the road. Because I'm a patient person and this was my
personal machine, I shelved the issue and moved on to more important things.


Fast forward to today. I'm considering building my first Windows 10 machine
that will be used by my user, so now we're working with different hardware
completely. I get the machine all built, domain joined and all is well. Then
I notice that one of our mapped drives "J:" is not showing up. We have some
applications that look at configurations that sit on this drive and when I
try to use them they complain that they can't find the file. Now, this is
where things get weird. I drop down to a command prompt and I switch to the
drive, and it's there! I can list the files, change directories, etc. But,
it's completely unavailable to Windows. See the screenshot at the bottom of
this email and you'll see me listing the mapped drive, but not able to
access it. Running a gpresult says that the mapping was a success.


Unfortunately, this isn't 100% reproducible. The next startup, all drives
could be mapped and available, or one or more might be like this. I do allow
time for the processing of the GPO, I'm on a gig wired network connection
and the system is a 3rd Gen i7 with 16gb of RAM and an SSD.


Anyone have any thoughts?



Mickey Mossey

Senior Associate Director of Information Technology

Programming & System Administration

University of Vermont Foundation


Personal Line:   802-656-4133

IT Main Line:    802-656-8310


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