Windows 8, Cloud, Security & Malware

[Ultravires]

Not really trying to stir anything up, but i was just wondering about how Microsoft would deal with the malware or viruses that might possible happen on there new O.S and what kind of security or measures they have in place to deal with it. I was thinking this scenario; for example, just say i was logged into my profile on my device and was unknowingly infected with some form of malware. With the new O.S, i can now access my profile on other windows 8 able devices. Now, just say i was to log in to my friends device using my profile, would the malware still be present or would it infect there device? Another scenario would be, just say my friend was to log in with their clean profile on to my infected device, would they become infected or what would happen then?

[Ultravires]

delete this post, since it is double posted, don't know why it keeps double posting!