An adware virus with a windows update?

Before you say anything i'm not talking about your run of the mill scam updates, im talking a windows update prompt, which I restarted my computer and installed, now Avast was magically installed and so was a nice adware virus, 2 actually, the other was webdiscover which I quickly got rid of. This virus is a pain in the "bottom" to track down. I couldn't find anything all the way down to windows processes out of the ordinary other than SVCHOST(a real SVCHOST) running. I have seen some complaints about ERDNT,LOC coming up as a virus but I think avast is actually picking something up. Every 30 minutes or so a website called Ragnarok arena comes up and at that exact same time ERDNT.LOC comes up as infected, if that isn't enough if I google "ragnarok arena adware" my google will instantly close out, and at that same time ERDNT.LOC comes up as infected. so far ERDNT.LOC is the only lead I have on how to get rid of this virus so I am asking for help, any no about this virus?

Hello Bob,

We are not sure if windows update caused this issue. Let's have a look at it. Have you installed AVG Antivirus free earlier and it got changed to Avast free?

Hello Bob,

We are not sure if windows update caused this issue. Let's have a look at it. Have you installed AVG Antivirus free earlier and it got changed to Avast free?