As mentioned in title, Internet stops working on my PC after heavy downloading, video/audio streaming etc. There are no errors, no disconnections etc. Simply after some time (certain amount of data downloaded) I can't get any more. If I try using ping afterwards nothing happens. If ping is running simultaneously with streaming/downloading I get some correct responses and then it keeps showing an error. What helps is re-plugging my Pentagram USB wifi card, but I hope there is a better solution.

Edit: One more thing: my friend who works in IT suggested that it might have something to do with cache (DNS cache? I don't remember him specifying) getting filled while it should be emptied automatically.