Corrupt downloads

[buckleb]

Over the past few weeks I've noticed an increasing number of corrupt downloads.

I don't download much at all, but I do get a number of email attachments each day. When I download these, the file is usually corrupted and I have to retry until I get a 'good' download.

Today I tried to download Defraggler. Every single site I visited gave me a corrupt download. I tried the previous version (Filehippo allows that) with the same results.

I have also noticed that when I download pictures (I have all my photos backed up online), I get that strange cut-off effect on jpegs. I've tried with http, ftp and my download manager. All give corrupt results.

Has anyone else been experiencing this? I'm on the 50Mb service running Windows 7 and Zonealarm Pro. I've checked for viruses trojans, malware etc, I've defragged and also rest Zonealarm. I've even turned ZOnealarm off.

I noticed a rather long thread about corrupt downloads on the Virginmedia help site. But to be honest that site seems to be anything but helpful, with no information or clues and a horrible ui that makes searching more difficult than it should.

Any ideas? Have any VM people heard about this as an issue?

Thanks.

---------- Post added at 10:04 ---------- Previous post was at 09:51 ----------

To add some more information. I've now been able to download defraggler. It took 7 downloads to get a good one.

I've had the same issue on my laptop, where downloads are not reliable.

Re the photos. If I persevere, I can usually get a 'good' one, but it's becoming a real pain to do so.

I've also tried a direct connection to my modem, but that made no difference.

[Kymmy]

I doubt if it's cause by the modem/connection, you could though try another PC on it first - Sounds like there's something on your system that's corrupting the downloads (firewall, AV, malware)

Try a hunt through a Hijackthis log file to see if anything weird pops up

[buckleb]

I should have detailed what I'd actually done when I mentioned that I'd checked for viruses.

I've run hijackthis (2.0.4 Windows 7 compatible one), ccleaner, superantispyware as well as a complete scan with Zonealarm. There's absolutely nothing there.

The modem also log looks normal, though I'm not sure what I'm looking for there.

It happens on my laptop and netbook, and also on my wife's laptop. I have a smartphone that seems to be OK, as does my internet radio device.

[Kymmy]

OK, now you've actually specified that it's happening on more than one PC (that is the crucial diagnostic) then the attention goes back to the modem/connection

[pazor]

Hi Buck

Sorry i wont be able to help but i can confirm this is a problem with VM and not the end user, I have had the same problem for about a year now you can search my posts and see the problems ive had. Every file is corrupt and have to redownload countless times to try what seems like locking onto a steady connection ( if that makes sence )
Again i know its not my pc as the laptop is the same and i even took my pc to my sisters and tried the same file.
I have given up on getting this fixed after being onto CS many times and being told to try restarting my modem :(
Fortunaly the items i download now have Par files that can repair the corupt data but getting any kind of updates drivers is a nightmare.
Goodluck and please let me know if you have a result.

[AbyssUnderground]

If you can, use an SSL connection for downloads. SSL can help prevent corrupt downloads to a certain extent.

I think every file should come with some sort of recovery of at least 3-5% these days. Connections are fast enough to handle 3-5% more and it saves the hassle of a re-download if a small portion is corrupt.

[Sephiroth]

There was also this thread on the VM forum with which I had a long association. http://community.virginmedia.com/t5/General-broadband-questions/New-to-VM-Corrupt-downloads-zip-rar-and-exe-files/td-p/5581/page/6

It was concluded (i hope not tentatively) that the Netgear router firmware was to blame. If you're Netgear, do try and borrow a non-Netgear router.

Did you try your downloads directly connected to the modem? If so and it's corrupt, then there's another potential dimension. Are the downloads standard HTTP or FTP downloads or are they torrented or in any other way multi-streamed? If torrented/multi-streamed, then I believe that the CMTS implements rate limiting which, in certain circumstances, can cause dropped packets.

Finally (and as Abyss has mentioned), on the VM thread, the SSL connexion did lessen the occurrence of corruption - principally because the download rate was reduced.

HTH

[buckleb]

There was also this thread on the VM forum with which I had a long association. http://community.virginmedia.com/t5/General-broadband-questions/New-to-VM-Corrupt-downloads-zip-rar-and-exe-files/td-p/5581/page/6

It was concluded (i hope not tentatively) that the Netgear router firmware was to blame. If you're Netgear, do try and borrow a non-Netgear router.

Did you try your downloads directly connected to the modem? If so and it's corrupt, then there's another potential dimension. Are the downloads standard HTTP or FTP downloads or are they torrented or in any other way multi-streamed? If torrented/multi-streamed, then I believe that the CMTS implements rate limiting which, in certain circumstances, can cause dropped packets.

Finally (and as Abyss has mentioned), on the VM thread, the SSL connexion did lessen the occurrence of corruption - principally because the download rate was reduced.

HTH

Hi Sephiroth (I recognise your username from the Virgin forums).

I don't use torrents at all and I can confirm that I have the same problem when connected directly to the modem. My router is not a Netgear anyway (it's a DD-WRT flashed Buffalo).

My setup hasn't really changed over the past year, and I only really started noticing this in the last couple of months.

I've tried downloads using the default Chrome browser download method. I've tried Firefox which calls my download manager (IDM) and I've tried Internet Explorer which calls the Zonealarm download tool. All exhibit the same fault.

The thing is that it is not consistent. It'll work fine for a little while, and then kick off again.

I'm not sure about the SSL thing, can that type of connection be used in place of a 'normal' connection?

I'm not sure what tools I can use to check anything on my end. My modem doesn't seem to have a huge amount of errors or anything, and I'm not sure if that's what I should be looking at anyway.

Thanks for the replies.