Netframeworks are up to 4.5 now...They don't typically cause network errors...
I still say that a virus is your problem...BSOD is typically related to hardware, not sorfware...Yours can also be a Vid driver issue that has crashed, BUT, it can be decieving, as a virus can and will cause these problems...Save your money...dump security essentials, and buy a Good virus program, or get a free trail..Most however are ###### today, including Trend, McAfee, norton, and AVG paid...PcTools is still my recomendation..as a reseller of it, I have installed and protected well over 2,00 comps with it trouble free..I swear by it....TIP...free trails don't always give you the needed definations to see and remove all Viruses/trojans.