Since Microsoft did not produce all of the software and hardware on your particular setup, nor how it is used, they may not be the one responsible for "those 0x800NNNN appear from time to time". However, since it is in everyone's best interest that your computer is not spreading diseases and may help them resolve other's issues like yours, they are willing to try and help you resolve Microsoft security-related problems for *-free-* . . . if you ask nicely.