Network connections box suddenly doesn't respond

Hi, I have a little problem that is pretty annoying. Sometimes, when I start some powerful tasks like rendering a video or viewing a full hd movie, my internet connection gets lost. To be more specific, all Windows network service stops responding, I cannot access network center and clicking on network icon in the tray does exactly nothing. The unique solution is to reboot the system but there is another issue, computer freezes at "Stopping work" or something like that, I guess, that's because that network process is broken and cannot finish himself. So I need to kill the system pressing power button. Ending svchost.exe network task in Task manager doesn't do anything it stays there like nothing happened.

Please, suggest how can I restart the service, when I get this problem and why it is happening. I use wifi adapter.
PS: I found this solution, but I am not sure if that's what I need:

Code:

Open the command prompt with Administrative privileges (if you press Ctrl-Shift-Esc and go to File -> Run, you can start "cmd" with Administrative privileges)
Type sc queryex netprofm | find "PID"
Note the PID that is returned.
Type taskkill /F /PID **PID_YOU_WROTE_DOWN_EARLIER_HERE** (without the asterisks)... e.g.: taskkill /F /PID 872
Type net start netprofm

Update:
I got this problem again and I started investigating more. In logs I found these four errors (when internet crashed):

The WinHTTP Web Proxy Auto-Discovery Service service terminated unexpectedly. It has done this 4 time(s).
The Diagnostic Service Host service terminated unexpectedly. It has done this 4 time(s).
The Network Store Interface Service service terminated unexpectedly. It has done this 4 time(s).
The Network List Service service terminated unexpectedly. It has done this 4 time(s).

Restarting Network Store Interface Service I COULD GET THE INTERNET BACK, without restarting the computer.
But when I googled "The Network Store Interface Service service terminated unexpectedly" I found only scary topics about trojans and other virus crap and now I'm kinda scared.

Kaspersky TDSSKiller didn't find anything but I still don't know what to do. Is it virus? I don't have any problems that I could relate with virus, only internet crashing..

Please leave some comments, I need an advice. Thanks

Why don't you get Kaspersky's Total Security free trial and run it, see if anything comes up?