Problem: From time to time my wifi connection download/upload speed goes to nearly 0 for 2-3 minutes (pages doesn't open) and goes back to the full speed after this time. This happens for about half an hour and then everything works good for another half an hour and then it's not working again... It doesn't happen on other computers connected to the same network and happens on 3 different networks.
Possible reasons: A few weeks ago I installed and played a little with aircrack. Maybe, I change some mode/setting in my wlan device by accident?