Final Windows 8.1 RTM version number may be 6.3.9600

As we get closer and closer to the end of August, it appears that Microsoft is still on track in terms of releasing its final RTM version of Windows 8.1 to OEMs sometime before the end of the month. Today, the Chinese site Cnbeta.com, claims that Microsoft is compiling the final RTM build and that the first sign off candidate will have the version number of 6.3.9600.16384.

The report also claims that Microsoft will quickly test the build once it is finished compiling and, if it finds no problems, the 6.3.9600 version will be the one that is sent to OEMs. A previous screenshot leak showed that the last build number for Windows 8.1 was 9484. Earlier this week, an older build of Windows 8.1, 9477, leaked to the Internet.

Microsoft has already announced that Windows 8.1 will be released as a free update to Windows 8 useres on October 18th and some OEMs will also start selling PCs with Windows 8.1 pre-installed on that same day. While Microsoft has yet to offer an official comment, it looks like TechNet and MSDN subscribers will not be able to download the RTM build of Windows 8.1 ahead of the general launch date, as they have for previous versions of Windows.

Thanks to Neowin reader FaiKee for alerting us in our forums!

Source: Cnbeta.com | Image via Microsoft

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Err, I could have told you this.

1. We already know that 6.3 is the NT version for Windows 8.1.

2. Final builds for Windows are always divisible by 400. Believe it or not this is some kind of policy within Microsoft, it has been in place since Vista. 9600 is the first possible candidate.

3. 16384 is where they start when they issue a new build. If there are issues and they need to rebuild, they will make a 6.3.9600.16385, then 6.3.9600.16386...

Aaron44126 said,
Err, I could have told you this.

1. We already know that 6.3 is the NT version for Windows 8.1.

2. Final builds for Windows are always divisible by 400. Believe it or not this is some kind of policy within Microsoft, it has been in place since Vista. 9600 is the first possible candidate.

3. 16384 is where they start when they issue a new build. If there are issues and they need to rebuild, they will make a 6.3.9600.16385, then 6.3.9600.16386...

Err! Wrong! The build number needs to be divisible by 16.

Studio384 said,
Err! Wrong! The build number needs to be divisible by 16.

Actually he's right...

It needs to be divisible by 16 and 100 so 400 makes sense.

This was posted by Faikee:
For vista/win7, there are certain rules governing RTM number, but these were not rigid like Newton's Laws or E=mc^2, or rather something like a ritual thing.

1. It has to be a multiple of 100: it started when a Exchange big-shot (forgot his name) took over Windows Section, simply because he likes major builds to have a 100-rounded up number.
2. It has to be a multiple of 16: the binary build string has 4 bits reserved to SP's, making available SP to be 2^4=16, RTM itself is SP0, so a condition for SP1 to install(among other things) is the target build number is a multiple of max. number of SP's, i.e. 16.
3. The RTM build string has a minor build number, the binary string has 14 bits for the build number, i.e. 2^14=16384, making available build numbers 0 to 16383, so the minor build number starts with 16384.

I don't know if MS has changed their numerolgy for win8, so there is no point in arguing over 8600, 8800 or whatever atm

Studio384 said,
Err! Wrong! The build number needs to be divisible by 16.

It has to be divisible by 16 and also by 100. So you end up with a number that must be divisible by 400.

timster said,
16384 ... Windows Vista RC1, RC2 and Windows 8 RTM all feature that number.

wonder if there is any significance to it


I think it's just something technical about their build setup. 16384 in decimal equals 4000 in hexadecimal.

the build no. takes 14 bits of the binary build string, 2^14=16384, so build no. could be 0~16383, and the minor build no.(delta) starts from 16384.

timster said,
16384 ... Windows Vista RC1, RC2 and Windows 8 RTM all feature that number.

wonder if there is any significance to it

The first sign of candidate of Windows 7 was also build 6.2.7600.16384, they Always start with 16384, every time there is an issue and they have to sign off again, that number goes one up.

This would really be rotten if MSDN and Technet subscribers had to wait until October 18 to get the new build. Especially since my Technet subscription expires 9/22. And I really can't see renewing, since the service is being discontinued.

It would be pretty dumb to not let MSDN folks have it. That would mean it would be impossible to have 8.1 targeted apps at launch. That makes no sense.

It should be 8.1.9600 ... If changing the base version number from 6.3 to 8.1 breaks compatibility, then that's a sign of horrible software design. It's Windows 8.1, not Windows 6.3

sabrex said,
It should be 8.1.9600 ... If changing the base version number from 6.3 to 8.1 breaks compatibility, then that's a sign of horrible software design. It's Windows 8.1, not Windows 6.3
It is Windows v6.3, live with it. And yes, it is a sign of horrible software design, but not by Microsoft, but by it's OEMs.

Anyway, Windows 8 was Windows v6.2, Windows 7 was Windows v6.1, Windows Vista was Windows v6.0.

So someone takes an educated guess at build and this is the main news / what the comments are about not that its compiled or that MSDN and Technet might not get it early?

OFC the build will be 9500 or 9600.

This is what happens when u become a slave to advertising revenue from page views. You create articles out of nothing. Might as well have an article about every possible factor of 16 that's above the current build number.

Just so you guys know the 6.3 is the kerne build numberl not the version of windows and I'm sure there's many people that do know that and just have not posted it yet
They could of called it windows 2013 or any other name for the matter at this point seems as though they have stop with names like vista XP win me and looks like they taking back up calling it windows and a number so as to show that its the next version of windows ya know like 1 2 3 7 8 8.1 8.1 being a update to windows with 8.1 being just a minor update and the next major build most likely be windows 9 and then maybe another 9.1 after that

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