I had installed and reinstalled two time today and i didnt got some virus messges on my comp.
I think that you have some hijak or infected ofline files somehow.

Shut down all processes//AV too// and clear ram with ram booster or somthing
clear all kind of temp files. And do install agane. // if no one monitoring you pc and changes packets that sends to you (if it is possible) so you will install it without some viruses.

//check you start up files

good luck