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).
This web site has been very helpful for some of the problems that I have had and I have been able to tweak the router and windows networking process.
I don't see how it can help. It is about optimizing and improving a good connection, rather than troubleshooting a faulty one. Something that doesn't work at all can't be tweaked to work better. The tools just fail with timeouts.