Today is one week since i changed network adapter. No BSOD. I did not turn off my computer at all, only once windows restarted it for automatic updates, but it was on for a week, playing demanding games (running 2 same time), downloading torrents, burning dvd's, many programs running simultaneously and not a single BSOD. So, i guess, it was faulty integrated network adapter or lack of good driver for it. Thanks all who tried to help.