Maybe there's already a rootkit on your machine, and the sure way to get rid of it is wipe and reinstall with a genuine disk. For me, it's faster and easier to reinstall than repeat the scan/repair cycle and hope it's clean.

I have been doing this for many years, but my approach is slightly different. I put the important work in the virtual machine and treat the physical machines as disposable platforms. If the hardware malfunctions, just transfer the virtual machine to another physical machine and resume work. Another plus is that it's easier to lock up and protect the virtual machines. There are limitations on 3D rendering, but all other tasks work just fine as on physical hardware.

I am decidedly minimalist wrt software configuration. I usually use the OS's built-in driver over SetPoint, unless I need to tweak the button functions. Fewer software means fewer vectors. This especially applies to plugins like Adobe Flash and Java. I would install them only if I really need them, and set the browser to "click to play" the plugins instead of automatic.

If the missus only uses PC to web browse, can't it be done on a tablet? Surfing Chinese web sites on a PC is risky. One wrong click and you get a new zero day exploit and root kit.