Both corporations are huge. They aren't going away, especially Microsoft. Facebook will be around as long as social media is around which won't go away.

Music to my ears.

Don't look at me like that. I'm using Chrome, and for some reason for me this forum is extremely buggy. It is a pain reading the posts properly. So, forgive me...

You're fine, I just noticed lots of people were not seeing the date due to it being an ancient necrobump, even though the point of the necrobump was to point out how off on the time predictions he was.

I use Chrome, I don't have too much problem, but the ads are very broken and appear in weird places and don't scroll right. It's not as bad as Internet Explorer though.

I think that's impossible.

They won't disappear, but they'll lose power. FBK will see its power resized due to scandals, but despite them people still prefer it to other social networks by a large margin, and more than a billion people won't drop it due to the network of relationships they established on it.
OTOH MS won't disappear due to its presence in enterprises, but due to competing mobile OS' replacing Windows PCs for many home users, it will receive less money from that market that up until now allowed it to offer enterprises a competitive yet highly profitable product, so it will have to find a less favourable compromise between Windows profits and competitiveness in the business market. It won't disappear anyway, and it will remain profitable, but eventually it won't be able anymore to conquer slices of new markets with the brute force of its huge cash, as divisions losing money to keep or increase market share will gradually become more significant for the company's balance.

Microsoft has already vanished from the embedded and high-end server market. They're losing server marketshare and slowly are (very slowly) losing ground on the desktop. Wouldn't be surprised if Microsoft becomes a Linux vendor. Their own cloud OS is basically a Linux distro.

Microsoft won't vanish anytime soon.
Facebook I could very well see disappearing at some point in the nearer future. (sub 10 years)

Most people just don't care about it, and FBK, although very far from perfect, is still the easiest and widest social network. Twitter sucks a lot in comparison, and it allows to make fake accounts even easier than FBK, the only reason mercenary trolls weren't as successful on it as FBK ones to screw elections is that unless you are already famous, most of your tweets get lost in a primal chaos of other usually useless tweets (FBK posts and comments can be as insignificant as Twitter ones, true, but its far less frantic pace makes social interaction easier, deeper and more enjoyable).

More chance of the Free Software Foundation of Europe vanishing in 5 to 10 years.