I thought a clean install would as well, the changed files for me we dsound.dll and debug-console-enabler.dll, so see if those are loitering?
Unless they are saved somewhere else, like in the documents folder?
All I can say here is quen is your friend, with dodge and holding block.
Unlike mobs in most games, beasties that attack in groups will coordinate: some will try to get round your back for extra damage, while their comrades have a go from the front.