What we know so far about the unusual Windows 10 1909

Microsoft has acknowledged that this fall's "feature upgrade" for Windows 10 will be virtually identical to the already-available version 1903 released in May.

"19H1 and 19H2 share the same servicing content. That means they share the same Cumulative Update package," Dona Sarkar and Brandon LeBlanc, the spokespeople for Microsoft's Windows Insider beta testing program, wrote last week in a post to their group's blog.

Sarkar and LeBlanc referenced 19H1 and 19H2 - better known perhaps as 1903 and 1909, respectively, in Microsoft's four-number labeling format - because their team had just released those builds to the Release Preview ring, where a subgroup of all program participants do a last test of betas.

Although Sarkar and LeBlanc did not explicitly say so - Microsoft rarely puts things plainly - their explanation confirmed that the fall "upgrade," 1909, will be nothing like previous Windows 10 editions. Instead, it will be a barely changed retread of the spring's 1903.

That Windows 10 1909 will resemble an old style "service pack" was not news: Last month, Sarkar and LeBlanc touted the refresh's small number of features and their even smaller import. Both were central to the characterization of 1909 as a service pack, as that format rarely included new features but instead collected past updates. (Microsoft's last service pack was for Windows 7, issued in early 2011.)

The two went into even greater detail about why Insider delivered two builds, 191H/1903 and 192H/1909, to the Release Preview ring.

"For the small subset of Windows Insiders (the 10%) in Release Preview who were given the option to install 19H2, an enablement package is downloaded from Windows Update that turns on the 19H2 features," Sarkar and LeBlanc wrote. "This changes the build number for the OS from 19H1 Build 18362 to 19H2 Build 18363. Because they use the same servicing content, the build revision number (the number that comes after the dot) will always match between 19H1 and 19H2. As we continue to test our servicing packages in the Release Preview ring, Insiders on 19H1 and 19H2 will get a single Cumulative Update with the same fixes."

It's parsing time

There is worthwhile information in what Sarkar and LeBlanc said in the quotes above. It's just that it's buried in terminology no one outside Microsoft's development team needs to know, surrounded by unnecessary verbiage that few understand or find useful.

Here are the bits that, teased from the rest, proved important.

Here's what we know so far about 1909

To recap what Microsoft's divulged so far: