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From time to time, web pages don't open or open slowly, downloading big files stop after a few KB or MB (no errors are thrown, just no data is received). Sometimes it works, sometimes it doesn't (recently the latter is more often). Sometimes unplugging and plugging in LAN cable helps for a minute or an hour, sometimes doesn't.

This is (probably) not caused by:

  • ISP: Internet on my laptop always works;
  • Router or cable: if I connect laptop through cable, it works;
  • Network adapter: installed a new one, didn't help;
  • DHCP: I've assigned static IPs;
  • Viruses: Kaspersky AV with latest updates installed and working.

I have no idea what can cause this. Any ideas? Can getting a WiFi dongle help?

Additional information: some time ago, LAN connection started dropping from time to time. Windows's "autofix" always fixed the problem and told about unavailability of default gateway. This problem was most prominent when downloading a lot of data through the network (I watched movies on TV through DLNA). After some fiddling with driver settings (disabling power saving and disabling flow control among others) the issue went away.

Windows 7 SP1 64-bit (all updates), network adapters Atheros L1 Gigabit Ethernet 10/100/1000Base-T Controller (built-in) и D-link DFE-520TX Fast Ethernet PCI Adapter (for comparison), router ASUS RT-N56U (cable for PC, WiFi for laptop, the latest firmware), ASUS P5K motherboard, Core2 Duo (computer is pretty old).

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There were some good suggestions when I asked a similar question at…. I had a wall of books between my router and computer that didn't help, although that certainly wasn't the only problem. – thursdaysgeek Jan 4 '13 at 21:38

Have you considered that it may be some problem in your OS? Try booting a Linux live-CD/USB on this machine and play around online for a while. This can help rule out the possibility of a problem in your Windows installation. Try a mature Linux live-CD/USB like Ubuntu, Linux Mint, Fedora, etc so that you can be sure it supports your NIC.

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Now that you mentioned possibility of software issue, I remembered that AVP doesn't like Comodo much. Not very convenient experiment, but I'll give it a try. – Squidward Jan 5 '13 at 11:15

I had an issue once with my network driver. Everything worked fine untill one day.
It appeared that the driver was updated by Windows Update, since then all my local connection were limited to 350kbps. Sometimes I had drop outs as well. I had to rollback the update to fix it, so the newest driver doesn't mean the most bugless.

Try to find another driver (try one not from windows) and check the driver settings. It could be that those settings will also be applied to other network adapters.

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The first card's driver provider is Atheros, dated 2009, the second one's is D-Link, dated 2009 (it's the only driver for Win7 in existence). And I have disabled driver updates in Windows Update. So I don't think this is the source of the problem. – Squidward Jan 5 '13 at 11:20

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