After using my computer for a while (30 minutes to an hour) i suddenly lose internet connection and my sound is also disabled. When trying to click on my internet connection it displays on the screen for a split-second and then disappears. no web pages load. if i single-click on the speaker icon in my taskbar nothing happens. if i double click it i get an error message saying "no mixer devices available...". Another symptom is that my taskbar goes from a double line (as i like it) back to a single line. Resetting the computer fixes the problem, but after using it for a while the same symptoms occur.
I have formatted my entire HDD numerous times. I have antivirus and malware removal tools. The problem still occurs. I used to think it was from an infected flash drive but i formatted and downloaded all apps from scratch (starting with antivirus).
I am fairly sure that it must be a virus that is coming through my network connection from a friends computer on the same network, but It doesn't show up in virus scans or malware scans (i have the latest updates). i have seen various fixes for the symptoms (like how to get your sound to work again), but this does not fix the cause of the problem and it simply reoccurs. another friend on the same network (there are 3 of us) has the exact same problems, although he usually gets a win32 error before the symptoms occur, yet the other friend who has no firewalls or any antivirus remains unaffected (which i find very strange).
I suppose the other possibility is that it has affected the boot sector of my HDD, or something complicated like that.
I have a fairly good understanding of computers.