Microsoft is "trying to ruin the PC as an open platform", according to Markus Persson, creator of the popular Minecraft game, commenting on Twitter. Shortly after I saw a tweet from developer Casey Muratori, "I am very sad to say that Windows 8 is apparently going to be a closed platform. Why isn't anyone covering this?"

The issue has been covered, of course. Microsoft was clear about this (with the exception of one aspect) from the first detailed unveiling of Windows 8 in September 2011. In the Windows 8 dual personality, the desktop side is an updated Windows 7 and apps are installed in the same way, from setup files obtained from anywhere, but on the touch-friendly side formerly called Metro, apps are, for most of us, only installed from the Windows Store.

The ARM version of Windows 8, called Windows RT, is where the lockdown really bites. No desktop applications can be installed at all, so it is Windows Store or nothing for consumers.

The rules are different for businesses deploying custom apps, and this is where Microsoft has not been quite so clear. Deploying apps without the Store is called sideloading, and is possible subject to certain limitations. Sideloading is described here. In summary:

• On Windows 8 Enterprise edition, you can sideload by setting a registry key and signing apps with a trusted certificate.
• On other versions of Windows 8, including Professional and the ARM edition, you need to "activate the sideloading product key" before sideloading will work. What is this? It is not clear, but normally a product key means the long serial number used to install Windows. This does not sound like something that most users will have access to.
• Developers can install apps using a developer license, but such licenses will expire so this is not a long-term deployment option.

The immediate conclusion then is this:

• The desktop side of Windows 8 on Intel is equally open as older versions of Windows
• The tablet side of Windows 8 is designed to be restricted to apps downloaded from the Store in most cases, other than for businesses with custom apps

Since Windows 8 on Intel is open on the desktop side, smart people will likely soon work out how to overcome app restrictions on the tablet side as well. Windows RT may be more challenging, but I imaging jailbreaks will come along for that as well. The rules still make a difference though, because only a minority is willing to hack their machines.

Is this the beginning of the end for Windows as an open platform? That is an interesting question, and I have seen predictions that the desktop will wither away, such as this from former Microsoft employee Hal Berenson:

The Start menu, and indeed the entire desktop, are legacies that will have to be removed from Windows over time.  While the desktop itself is probably with us for a couple of additional major Windows releases (though there may be truly desktop-free editions sooner than that) ...

Still, even if Berenson is right, desktop Windows on Intel will be with us at until Windows 10 in say four or five years time, which means maybe six or seven years before a potentially desktop-free Windows 11. None of us can see that far ahead though. If Windows RT takes off, we could be thinking of Windows as mainly a tablet OS much sooner than that.

On the other hand, if the tablet personality in Windows 8 fails to achieve its goals, desktop Windows may remain the main version forever until Windows fades away.

Nobody knows, though it is fun to speculate. However, it is interesting to examine why Windows is becoming less open and whether or not this is a bad thing.

Microsoft could not get away with this so easily without Apple, which came up with the "App store only" model for the iPhone and iPad. That makes them closed platforms, and makes Apple a ton of money from store fees, but users are happy because app store prices are generally low, plenty of apps are free, and there is no uncertainty about "where do I get apps for my iPad?", and the App Store is curated so that it should be malware-free, and if malware were to sneak through, it would soon be removed.

In a business context, where administrators want full control over which apps are installed for security and stability reasons, a closed platform is mostly a good thing. A closed platform in combination with the sandboxing of apps on the tablet side is a very good thing.

What about open source? What about consumers? There are fundamental objections to closed systems, which inherently put too much power in the hands of the platform owners. How can we be sure that Microsoft, for example, will not favour its own applications over competitors for things like Office? This is already the case with Windows RT, which comes with Office pre-installed and no way to install an alternative on the desktop side.

On the other hand, the openness of Windows, once a benefit as it encouraged a strong application ecosystem, has become a disadvantage. Users love the performance, stability and clean user interface they get on an iPad, versus Windows machines which more times than not are spoilt by apps running on startup that are not needed, mysterious toolbars that appear unasked in web browsers, along with adware and sometimes malware.

Anybody looking at Windows today would conclude that the system needs to be brought more under the user's control; and that is hard to do without lockdown. Windows Store apps in Windows 8 are easy to install and, more important, easy to remove.

There is every likelihood than that both businesses and consumers will see the lockdown in Windows 8 more as a benefit than a burden; which is actually a good reason for those who may in consequence lose out (like Valve which runs a games store for Windows) to shout loudly about the issue.

The case is not simple though, and on balance most users may well be better off with a less open system than they currently enjoy.

Finally, remember that Intel Windows 8 on the desktop side remains as open as ever, and will be for the foreseeable future.