If you ask that on Slashdot, you get either "switch to Linux hur hur" or "they should write a new OS from scratch and run NT in a VM." Neither of those is a realistic option. The second is (slightly) more realistic, but it would be a decade of work even assuming MS started this minute.
Oh pish-tosh. Show of hands...how many people have a Windows VM up and running? Wow. MS doesn't even have to do anything...Dell or some other OEM could bundle machines with Linux, VirtualBox, and a Windows VM with snapshot facilities. And not even tell people there's Linux under the hood. And in case you get pwned, just revert back to a clean snapshot (like the one provided out of the box).
The only parts that would take a decade is to get graphics working (eg games). and 'weird' hardware (that has no Linux or Mac ports).
Of course, virtualization would commodatize Windows, which would interfere with MS's business model. So I don't think they're too eager to go that route.
So I guess that answer is not realistic for MS anyway. After 5 years, I believe MS *is* doing everything it can (w/o saccrificing its business model). If they haven't fixed things, maybe they *can't*.