Some web downloads stop part-way through

3

I am running Windows 7 Home Premium 64 bit.

The majority of files I download complete without error, but some stop part-way through. This happens on all browsers.

Some stop at a random location (multiple attempts stop in different places), whilst others are consistent.

For example, downloads of the CentOS DVD ISO from here (regardless of which link I click) stop at 15MB every single time.

The problem only happens on one computer, others on the network are fine. The connection is wired via Cat5e ethernet cable.

The problem also occurs when the computer is connected directly to the internet via the modem, bypassing the router and any other devices.

I've tried using an Intel gigabit network card instead of the in-built Realtek but the problem persists.

I disabled my antivirus software also, no difference. I do not run any firewall software on the PC itself.

The problem does not appear in safe mode with networking.

My internet speed is approximately 40mbps down and 20mbps up.

I'm seeing "TCP Acked Unseen Segment" in Wireshark, unsure if that anything to do with it.

SDB

Posted 2015-06-01T12:45:25.937

Reputation: 33

are you behind a proxy server? – Francisco Tapia – 2015-06-01T12:57:13.813

Nope. In fact I even connected directly to the modem using PPPoE and the problem persists. – SDB – 2015-06-01T13:00:01.630

Try downloading in an incognito window in chrome. – Cosco Tech – 2015-06-01T13:10:34.713

Same issue in Incognito. – SDB – 2015-06-01T13:27:26.150

1the answers could be very wide, since Intrusive Antivirus Protection/Firewall, some SOHO networking devices features as Block Fragmented IP Packets or even PHY issues, we espect more research, the question is good but still missing research. – Francisco Tapia – 2015-06-01T14:14:41.350

I edited the question, hopefully it is clearer now what I have tried. – SDB – 2015-06-01T16:33:01.013

1Since when did you start experiencing this problem? Have you installed new hardware/software recently? The problem does not appear in safe mode with networking. - I think this is key. Some proxy/security software causing the problem perhaps? – happy_soil – 2015-06-02T14:22:12.967

It has been happening on and off for at least a year, but lately it's happening more frequently and affecting more files. No hardware has changed since the problem began. In April I did upgrade the internet connection from 10mbps to 40mbps, and it seems like it might have worsened since then, as if it "can't cope" as well with the higher speed. Maybe a coincidence. – SDB – 2015-06-02T15:37:16.337

After some more checking I think this may be related to the filesystem? I used fltmc to unload the MBAMProtector as I thought that it might be the culprit. I tried the CentOS download and it got past 15MB, though on subsequent tries it's stopping at 15MB again. But could that temporary success mean a filesystem issue? – SDB – 2015-06-02T15:55:55.573

Answers

0

You've narrowed down the problem pretty well. Here's what I can deduce so far:

  • It's highly unlikely an edge-network connectivity, e.g. modem/router issue.
  • It's unlikely a [PC] hardware problem, at least on the networking-side
  • It's likely a software running in the background causing the problem.

Here are a few more things to try, albeit a little more significant and perhaps time consuming:

  1. Boot a Live CD, e.g. Ubuntu.
  2. Set up a virtual machine, e.g. VirtualBox.
  3. Re-install Windows.

happy_soil

Posted 2015-06-01T12:45:25.937

Reputation: 2 339

Even though I was sure I'd disabled it properly, checking again reveals that the problem was Bitdefender Free Antivirus. Seems that it was proxying all web traffic or something. Don't know why nobody else seems to have the same issue, I guess there was a conflict somewhere. After replacing it with another brand the issues have stopped. Thanks guys. – SDB – 2015-06-07T22:27:27.037

Asked: 2015-06-01T12:45:25.937

Viewed: 131 times

Active: 2015-06-03T08:12:20.633