A few days ago, my wife hit the same thing following a link in a perfectly benign google search result! she would have had no idea how to untangle this by herself, since I had failed to turn off firefox restore on error so killing and restarting firefox got right back to the problem.

Infected windows machines are a plague on the internet. Many of these presumably have no useful anti-malware running. Microsoft takes lots of heat, as the comments above prove. So Microsoft decides that trying to sell anti-malware won't work, but maybe giving it away, and I assume bundling it, will get it widely deployed. And take some heat off Microsoft for shipping vulnerable stuff. If this happens, and it works at all, it will be a great improvement to the current mess. To put it differently - it's clearly impossible to make an OS bug proof - so an OS ought to contain defenses against malware out of the box.

Lots of misunderstandings in the replies. First - the most common offender is the Hotel's local internet service. Second - this is about DNS, not routing. Windows tries all the DNS servers at once and believes the first positive answer. The DNS servers in the story are the onces the Hotel gave you on the real interface, and the ones VPN gave you on the VPN interface. You can often make this go away by using the advanced settings in the network folder to order the VPN adapter first as a service provider. Failing that, I know of no solution that doesn't require messing with the DNS server entries in the real adapter.

Proofs and Refutations by Imre Lakatos takes the reader through an apparently simple and obvious mathematical theorem, and by the end has you deeply aware of how subtle mathematics really is.