Can't copy big files off my C: drive

Click on start, keep the shift key pressed and click on reboot. This will allow you to see the advanced startup options where you will be enabled to start in safe mode. Within safe mode, retry with your memory stick for a test.

@Mknife: I just tried safe mode and copying to my USB stick was fine, but to confuse things now I rebooted back into normal mode, copying to my USB stick is still fine. I can't copy the same files to the network though.

@Arnold: The only antivirus we use is windows defender. I tried copying from the network to my C: drive and it succeeds every time.

Try setting up a new share, and exclude it from live scanning,
There is no way for me based on the information at hand to guestimate other causes.

You should do more tests, this time in safe mode with networking. At the moment, there is no indication that it is AV software. Defender is not known for producing such an effect.

My suggestion is initiate the copy while logged into the Windows server copying data from the Windows 10 system
I.e. You can while on Windows 10 copy data to Windows 2008
The opposit while logged into Windows 2008 copy data from the Windows 10 system.

if a scan exists on a read is not the same as a scan triggered on a write...

I set up a new share, and added an exclusion to Windows Defender. I still got the same behaviour.

I tried booting into safe mode with networking. All my drive letters were visible, but with a red cross through them even though I had logged on properly. So I could not attempt the copy.

From the server I tried copying from my workstation and pasting the files onto the same share. It works every time and its much, much faster than what I am familiar with when I copy from my workstation to the server.

In safe mode with networking, please retry and find out if you can access the UNC paths \\server\share instead of the mapped drives. please note that red crosses often appear when the network is not initialized while you logon - seconds later, these drives may be accessible although windows explorer still shows red crosses - so simply try to access those after a few seconds.

Ok I tried safe mode with networking again, and waited a while after logging in. The UNC paths didn't work either. I tried \\Servername\sharename and \\ServerIP\sharename.

I tried copying from 2 other workstations onto the network. One workstation was ok, but the other behaved just like my machine. So maybe this is a server issue?

Nothing changed on the server apart from the windows update which happens most weeks on the server. I have it scheduled to update every sunday afternoon. But this issue only started last Thursday. Monday through Wednesday everything was OK.

Schedule the server to reboot at any time you find suitable and retry.

Actually I just remembered, something maybe has changed.... Because one user complained of speed issues, I tweaked a setting on the server NIC. I'd better check that out.....

You better :-) That could very likely be the reason, I wouldn't be surprised.

Can you move the file locally - don't go off the network - copy to a USB drive or another partition or physical disk within the server.  Does that work?  (You want to eliminate the possibility that the hard drive/RAID array has issues).

>I tweaked a setting on the server NIC.

That wouldn't have anything to do with duplex settings by any chance?

I would remove the network adapter and re-add it again via device manager.
Plus try copying with windows firewall disabled.

@pgm554: No, i'd read somewhere that the "Large Send Offload" feature could cause problems, but I'd already dismissed that as being the cause and re-enabled it before my file copying problem started. So as far as i am aware the NIC settings are now back as they originally were.

@Lee W: From the server I can move files around to any location and also push/pull them to and from my workstation across the network. My problem only exists when I attempt to initiate a large (40M+) file copy from my workstation.

@noxcho: I don't think i'm brave enough to down our server and remove/re-install the network card.

A bit more background information on this.... Before this file copying issue started, I was already investigating an issue whereby network transfer rates seem to deteriorate after the file server hasn't been rebooted for a while. I use a utility call Lan_SpeedTest.exe Immediately after rebooting the server it typically gives me read/write speeds of 600/300 Mbps. I rebooted the server last night and got those readings just afterwards. This morning 16 hours later i am getting speeds of 300/150Mps. Last week when someone complained about the speed I ran the test and found I was getting 30/15Mbs. Everytime I reboot it goes back to 600/300Mbs for a few hours. Maybe this is related to my file copying issue? Maybe it isn't and I shouldn't be mentioning it in here.

I would like to find a document somewhere which tells me what parameters I should set for the server NIC. It's a Qlogic BCM5716C. Thus far I haven't been able to find anything. As far as I am aware it is currently set up like it came out of the box although it's had a few driver updates down the years.

@Lee W: The switch is a Cisco SG300-28. I don't reboot it when I reboot the server..... Or are you suggesting that the switch could be throttling the bandwidth in response to what it thinks it sees?

Sg300 is a 10/100 if not mistaken.check switch for error events,

Reboot the switch or temporarily replace it and see what happens if you can't find errors in its logs.

@Arnold: SG300-28 is a gigabit switch.

I've found a cure! But i'm not sure it's the right cure.....

For many years It's always been a habit of mine to disable IPV6 on every workstation NIC. We dont use it and i've never seen the point of having it enabled. I know that Exchange can get a bit moody without it, so I leave it enabled on the server.  Just for the hell of it I enabled it on my workstation. My file copying now succeeds. Just in case it was a fluke I disabled IPV6 again and got my original issue back. I've enabled it again and I can copy files again.

So does this mean that IPV4 is broke somewhere?

No, it is not an issue with IPv4 but a response to a lookup on server that potentially provides a response containing two records, one IPv4 and one IPv6.

Seems you've identified the cause and found the solution to your situation.

I was assuming  that a fault had recently developed because I have had IPV6 disabled on every workstation forever. I think today is the first time a workstation has ever been configured to use it in our company. IPV4 has always had the legs required.

Did the windows 10 system apply the fall update, 1709? The issue coinciding with that event/timing?

No, and I just spotted when I looked in the update history that a cumulative update for build 1703 failed to install a couple of weeks ago. The only only recent update has been an Adobe Flash Player update on October 18.

hmmm.... when I try to manually install updates it says my machine is up to date, even though that cumulative update failed. My current build is 1703 (15063.674)

Does the issue correspond to the initial install attempt of the newer version?

No. The issue started on October 19th, my workstation attempted to install that update on the 15th. Copying these files is a task I perform multiple times every day as I publish program updates. I would have noticed if the issue was there from Monday onwards.

You found the solution.
I think it is coincidental, but might not be unrelated to the update attempt.

The other system experiencing the same issue, did they apply the newest update either way?

something led to the failure of install, but the rollback was not completely to the original state....

in the GPO try disabling the internet connectivity test, NCSI
computer configuration\administrative templates\system\internet communication management\internet communication settings\
enable turn off windows network connectivity status indicator active tests.

Annoyingly, the other workstation which exhibited this issue yesterday is copying files perfectly today (without IPV6). I've tried several other workstations and they are all ok also using just IPV4. My own workstation still has the problem though. I've uninstalled the NIC and re-installed it. I also tried that GPO tweak to turn off NCSI. I still can't copy my database program, or other database files to the server unless I have IPV6 enabled. By the way, every workstation is still on version 1703. The other workstations managed to install that cumulative update which failed on mine.

I'm loathe to leave IPV6 enabled because it is masking the real problem. But at least the IPV6 gives me a workaround to get me working again. Unless there are some other suggestions, i'm going to close this thread soon. One more question though... As far as I can see, EE no longer allows me to share the points. I almost closed this thread a couple of days ago and found I could only allocate the points to a single person. Am I seeing this right?

You can select multiple answers and even adjust points. When selecting a "best answer", just proceed on the same screen to select additional assisting answers and when you are shown who has been assigned how many points, you can edit that.

About your problem: Make sure that your server is still configured like before. Your "So as far as i am aware the NIC settings are now back as they originally were" does not sound confident.

The NIC settings on the server deal with prioritization for application, for fileserver .....

As mcknife pointed, you can only select one best solution, while can make as many assisting solutions. By default the selected question are equally weight.

Try using robocopy versus explorer based.
See if that makes a difference.

"By default the selected question are equally weight." - more precise: the best answer gets half the points while all assisted answers get the same share of the remaining half.

The point awards changed, the person answering with the best question gets the half of the points as you pointed out while the other recipients split the remaining no matter how many of each person's comments were selected.
I.e three of your comments are selected, one best solution, one of mine as assisted; we each will be awarded 500 points for a low priority question.

I have seen this go differently, but I will have to wait for a new question of mine... or look it up somewhere. Anyway, he can edit points to his liking :-)

I've just tried Robocopy and that works. I'm probably going to leave IPV6 enabled though, because it is so useful being able to copy and paste in Windows Explorer.

>>  Your "So as far as i am aware the NIC settings are now back as they originally were" does not sound confident.

I should have been more forthright. I only changed one server NIC setting, and I reversed it later. The server has been rebooted since then also.

I'll have another go at closing the question. When I tried previously, it looked like it was about to give all the 1000 points to my 'best' answer and didn't seem to be giving any to my assisted answer.

This has been a long, tortuous but well answered thread. Thanks everyone for your input.

Ok this time it didn't assign all the points to my best answer, and also this time I can see the button to edit the points. Probably just a glitch last time round. Thanks again guys.  Your input is much appreciated.

Ian