Windows 10 will power to its third anniversary this summer, but one branch, identified by the initials L-T-S-B, remains an enigma to most corporate users.
LTSB, which stands for "Long-term Servicing Branch," was among the pillars of Windows 10 in the months leading up to, and for months after, the mid-2015 roll-out of the operating system. For a time, it seemed that it had a shot at becoming the Windows 10 for enterprise because it was seen as a calm port in a storm of radical change.
That hasn't happened, in part because Microsoft has steered customers away from LTSB.
Just what is LTSB? And what has Microsoft done to make it an afterthought?
We have answers.
So what is Windows 10 LTSB? Officially, LTSB is a specialized edition of Windows 10 Enterprise that promises the longest intervals between feature upgrades of any version of the operating system.
Where other Windows 10 servicing models push feature upgrades to customers every six months, LTSB does so only every two or three years. That means fewer changes during a set timeline, a less-involved upgrade effort, and fewer disruptions as well as fewer possibilities for applications breaking because of a modification of the OS.
If LTSB stands for "Long-term Servicing Branch," what's this "LTSC" acronym I've seen bandied about? When Microsoft dropped multiple labels for Windows 10's release tracks - those now retired included "Current Branch" and the unwieldy "Current Branch for Business" - for the single "Semi-Annual Channel," it also debuted Long-term Servicing Channel" to match the latter.
Think of LTSC as the mechanism that updates and upgrades the actual operating system, which goes by the LTSB moniker. Yes, it's confusing. But then, it's Microsoft.
How often does the LTSC update Windows 10 LTSB? That's a question so good it comes with more than one answer.
1. Windows 10 LTSB does receive the usual monthly security updates.
2. The twice-annual feature upgrades delivered to other channels will not be offered to LTSB systems.
3. Microsoft upgrades the LTSB "build" every two to three years. Those upgrades, however, are optional, or at least optional to some degree (more on that later).
4. Each LTSB build is supported with security updates for a decade, the same 10-year lifespan Microsoft has designated and maintained for ages.
5. What's the current Windows 10 LTSB? When is the next one supposed to show up?The latest LTSB is designated 1607 in Microsoft's yymm naming convention; that's the version that debuted in mid-2016 and was labeled "Anniversary Update" by Microsoft's marketing.
The previous two LTSBs, versions 1507 and 1511, still receive security updates, of course.
Microsoft has said that the next LTSB will ship sometime in 2019 but has not revealed a release date. Because of Windows 10's standardized schedule, it will be named either 1903 (and released in March/April) or 1909 (September/October).
What's missing from LTSB? A lot that makes Windows 10, well, Windows 10. Eschewing the regular feature upgrades means that LTSB does not include Edge nor any Microsoft Store (Universal Windows Platform, or UWP) apps, whether Redmond-made or third-part, because the browser and those apps constantly change and need updating. Also AWOL: the Cortana voice-activated digital assistant and access to the Microsoft Store.
That said, LTSB looks and runs just like any other Windows 10 edition. No one will be fooled into thinking it's Windows 7.
Can we defer security updates if we're on LTSB? Yes.
Servicing tools such as Windows Server Update Services (WSUS) and System Center Configuration Manager (SCCM) let administrators delay the monthly security updates - which Microsoft calls quality updates - just as they can postpone those same patches reaching machines running other versions of Window 10.
Why does Microsoft make LTSB available to customers? Plainly put, it was a sop to the criticism very early on about Windows 10's accelerated development and release tempo.
Customers had become accustomed to upgrading Windows every three or more years, with the emphasis on more in the enterprise. The announcement that that would change to multiple releases each year - initially, three annually - was a shock.
Microsoft tried to soften the blow by offering a schedule very similar to the slower cadence familiar to IT: Upgrades that appeared every three years or so, with little or no feature changes in between, and an update model that provided only security fixes. In a nutshell, that's how Microsoft described Windows 10 LTSB at the start.
Although Microsoft always opined that LTSB was suitable only as a minority choice - one for special situations, such as machines that simply should not be frequently touched, like those that control industrial systems or ATMs - early in Windows 10, there was significant talk among IT administrators about choosing LTSB for broad swaths of their PC inventory.
Why? Because they weren't convinced they could, or even should, snap to and adapt to Microsoft's pitch of "Windows as a service" (WaaS).
Okay, so which PCs should be running LTSB? Here's what Microsoft says on that:
"Specialized systems - such as PCs that control medical equipment, point-of-sale systems, and ATMs - often require a longer servicing option because of their purpose," the company's primary Windows-as-a-service documentation states. "These devices typically perform a single important task and ... [i]t's more important that these devices be kept as stable and secure as possible than up to date with user interface changes."
"As a general guideline, a PC with Microsoft Office installed is a general-purpose device, typically used by an information worker, and therefore it is better suited for the [non-LTSB servicing channels]."
Has Microsoft changed the support rules for LTSB since Windows 10's debut? Yes, and in a way which makes it difficult if not impossible to widely deploy the edition.
Nearly a year ago, Microsoft added another law to the Windows 10 support scene, one that analysts contended largely invalidated LTSB's advantages over the shifting features that mark the other versions.
Originally, Microsoft promised to support each LTSB edition for a full decade. But in early 2017, the company ruled that "LTSBs will support the currently released silicon at the time of release of the LTSB [emphasis added]," and that as new processors appeared from the likes of Intel and AMD, "support will be created through future Windows 10 LTSB releases that customers can deploy for those systems."
The bland language disguised a huge change. Rather than be able to stick with a single LTSB edition for five, even 10, years, enterprises will need to adopt virtually every LTSB version as they buy new PCs powered by newser processors.
What's one of the least-understood aspects of LTSB? We'd nominate this one:
If the IT staff decides to switch PCs from LTSB to plain Windows 10 Enterprise - so those machines can receive feature upgrades - they cannot simply flip a switch. Instead, they must re-install Windows 10 Enterprise from media, then recreate the application and app collections on the device.
Another requirement: That Windows 10 license must be accompanied by Software Assurance (SA), the annuity-like payment program that provides free upgrades during the time of the licensing agreement.
How long is LTSB supported? Ten years is usually the answer you see to that one. But it would be, if not wrong, then misleading.
Windows 10 Enterprise LTSB is guaranteed only five years of support - from the time of its release, not its installation - if the underlying license does not have SA attached. With SA, a specific LTSB edition is supported for the full 10 years.
We run Windows 10 Enterprise and pay for Software Assurance. But we're thinking about dropping SA. Anything we should know? Yes, indeed.
When a company drops SA at the end of a contract period, it is entitled to roll out Windows 10 Enterprise LTSB only. Customers have a 90-day window to switch the current operating system from Windows 10 Enterprise to Windows 10 Enterprise LTSB. Note: To do that, Windows 10 Enterprise must be uninstalled before deploying LTSB.