At the minute I just have to put up with spending a few hours removing the worst offenders and then running several different adware removers. It generally keeps them running well for a few months.
I would love to set up a VM so whenever things start going wrong they could just delete the VM and start fresh. Currently VMs are a bit too heavy weight, a lot of people struggle with the concept of working in multiple Windows let alone knowing which machine they are actually working in. I am looking forward to Microsoft implementing containers ala Docker. It will be interesting to see what possibilities will be available for making it seamless and quick enough for a computerphobe to browse within a container.