The strongholds Windows still holds - 4/6

Third category: the segments where Windows is still dominant. They share a common trait, which we will come back to — most of them are old conquests, won twenty to thirty years ago against Unix, OS/2 or Novell.

The enterprise directory (Active Directory)#

Active Directory, the directory service of Windows Server — the one that manages accounts, workstations and permissions within an organisation — is used by the vast majority of large enterprises: about 90% of the Global Fortune 1000, according to the firm Frost & Sullivan. It is the backbone of corporate identity, extended today into the cloud by Entra ID (formerly Azure AD). This position is itself the fruit of a conquest: in the late 1990s, Windows NT Server supplanted Novell’s NetWare, which then dominated the file and directory servers of local networks.

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Industrial supervision (SCADA)#

SCADA (Supervisory Control And Data Acquisition) refers to industrial supervision systems: those that monitor and control factories, water or power networks, production lines. It is a historical Windows fief: its reference software is written for Windows — Siemens’s SIMATIC WinCC (integrated into TIA Portal), as are its competitors Rockwell and AVEVA. It is a conquest: in the mid-1990s, natively Windows NT supervision platforms (Wonderware foremost) dethroned the DOS- and Unix-based solutions.

The lock is not total, however, even at Siemens. Its other SCADA, WinCC OA (Open Architecture, aimed at large distributed installations), is cross-platform: it installs natively on Linux (Red Hat, Oracle Linux) as well as on Windows, and can even be deployed in containers. Linux solutions therefore do exist on the market — but no public per-operating-system figure says in what proportion they are actually deployed against Windows.

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CAD workstations (engineering and architecture)#

The major mechanical CAD software has no native Linux version: CATIA and SolidWorks (Dassault Systèmes), as well as Inventor (Autodesk), run only on Windows; AutoCAD (Autodesk) adds macOS. The lock is therefore an application one: it is the software that holds the system, not the other way round. And it is a Windows conquest against Unix: in the 1990s, CAD ran on Unix workstations (SGI on IRIX, Sun, HP); the port of CATIA to Windows NT (version V5, 1998) and the slow demise of SGI (end of IRIX announced in 2006) mark the shift — the falling cost of x86 PCs, and the arrival of Linux, contributed to it as much as Windows itself.

Architecture and construction are locked down even further: Revit, Civil 3D and Navisworks (Autodesk) are Windows-only, without even a Mac version.

This lock remains specific to these fields, however: film and visual effects, by contrast, were built on Linux (see the previous article). It is indeed the profession’s software catalogue that sets the OS, not Windows as such.

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Audio and music production#

Music creation and sound (for film as well as in the studio) rest on digital audio workstations (DAWs): a domain that Windows holds — but shared with macOS, not with Linux. The professional standard, Pro Tools (Avid), runs on Windows and macOS; Ableton Live, Cubase (Steinberg) and FL Studio too; Logic Pro (Apple) is macOS-only. Native Linux DAWs do exist (Ardour, Bitwig, Reaper), but remain marginal in the studio.

Unlike the image (film, VFX, moved to Linux), sound is therefore a Windows / macOS duopoly: Windows keeps an important place there, without dominating alone.

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Cash machines, terminals and kiosks#

Automated teller machines (ATMs) are a durable Windows stronghold, on Windows IoT Enterprise (the heir to Windows Embedded). The most-cited figure — ~95% of ATMs on Windows XP in 2014 — actually concerns the US fleet; but Windows’s dominance is not limited to it. In India, the central bank (RBI) required banks, in 2018, to migrate their ATMs from XP to a more recent Windows version (7 then 10) — not to anything else. And the sector’s next generation remains Windows everywhere: Windows 11 IoT Enterprise LTSC, which Diebold Nixdorf was the first supplier to support, in 2024. The fleet has therefore migrated from version to version — XP, Windows 7, Windows 10 IoT, Windows 11 IoT — but always on Windows; the attempt to move ATMs to Android (NCR, 2015) never took hold. It is also a conquest: ATMs previously ran on IBM’s OS/2, replaced by Windows through the 2000s.

One reservation, however: China is a blind spot. Its digital-sovereignty policy pushes a national Linux-based system (Kylin, then OpenKylin) into the financial services, and one of the world’s largest ATM manufacturers by volume, GRG Banking, is Chinese — but no public source says what system its fleet actually runs. For lack of figures, one can therefore neither confirm nor deny Windows’s dominance over Chinese ATMs.

Interactive terminals and kiosks follow the same logic as ATMs. Be careful not to confuse them with tills and payment terminals, which are shifting to Android.

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Enterprise servers (Windows Server)#

This is the honest counterpoint to Unix’s dominance on the web. On public web servers, Windows accounts for only ~8% — a figure that greatly underestimates its real internal footprint: Active Directory domain controllers, file and print servers, line-of-business applications, internal IIS servers, all invisible to web scanners. But by how much? For lack of a free public measurement, one must turn to paid studies (IDC’s Worldwide Server Operating System Environments Market Shares series) — and a dated anchor, the 2017 edition, perfectly illustrates the metric trap: the same report gives two opposite pictures of the same market.

By value (paid shipments and subscriptions), Windows is No. 1, at 49.6%, ahead of Red Hat (32.7%) — but it is declining there (−3.3% year on year) while Red Hat surges (+19.6%).
By total deployments, non-paid Linux included, the picture flips entirely: Linux 68%, Windows 31.7%, Unix 0.3%.

In other words, Windows Server dominates where the money flows, but Linux dominates the actual number of servers, by more than two to one. The web figure (~8%) did indeed underestimate Windows — its real footprint is about a third of servers — but, even corrected, Windows Server remains a minority against Linux in the server room. These figures are also eight years old — but the trend they showed has not reversed since: on public web servers, Windows’s share has kept declining, down to ~8% through 2026 (W3Techs), and the market’s recent strong growth has concentrated in the cloud, overwhelmingly Linux ground.

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A more nuanced case: hypervisors#

Microsoft has a hypervisor, Hyper-V, which makes one spontaneously file virtualisation among Windows’s strengths. The reality comes down to a paradox.

Hyper-V runs all of Azure, at a colossal scale: on that count, it is a real strength for Microsoft. As a data-centre hypervisor, on the other hand, it has never dominated: the on-premise leader remains VMware ESXi, with its own kernel (neither Windows nor Linux). No reliable current market share is available for free — the detailed measurements come from paid studies (IDC, Gartner) — but the historical order of magnitude is telling: Gartner already credited VMware with ~84% of the hypervisor market in 2010, against 11% for Hyper-V. Since then, VMware has gone through severe turbulence, following its acquisition by Broadcom (2023) and the pricing overhaul that came with it. According to a Rimini Street survey from late 2024 (111 large VMware customers), 98% are using, planning or considering an alternative, and 36% have already switched. The movement remains gradual, however: a CloudBolt study from January 2026 (302 North American decision-makers) finds 86% of companies reducing their VMware usage, but only 4% having abandoned it entirely.

Now, among those alternatives, it is Hyper-V that comes out on top: considered by 69% of respondents, far ahead of Oracle VirtualBox (51%), Red Hat Virtualization (48%), Citrix (26%), Nutanix (19%), KVM (11%) and Proxmox (10%). Virtualisation is therefore neither a held stronghold — VMware still dominates the data centre — nor lost ground: it is a contested segment, where Microsoft is doubly present (all of Azure, and the front-runner expected to capture VMware’s exodus). The paradox: Windows weighs heavily here, yet without ever owning the market.

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A common thread: these are old conquests#

These strongholds share a common history: Windows won them, and won them against Unix or its competitors of the day. File servers wrested from NetWare (1996-1997), CAD workstations wrested from Unix workstations (CATIA on Windows NT, 1998), ATMs switched from OS/2 (2000s), industrial supervision moved from DOS and Unix to Windows NT. Microsoft even conquered, in 2001, a market where it did not exist — the game console, with the Xbox — but that conquest has since turned into reflux: it belongs to the breaches, covered in the next article.

But all these conquests are old: they date from the late 1990s and the 2000s. Over the past decade, Windows has conquered no new segment — with one nuance, and one only: virtualisation, where Hyper-V is today taking advantage of VMware’s exodus to gain ground. But that means consolidating an old position (Hyper-V dates from 2008) in an already-contested segment, not conquering fresh territory. For the rest, the strongholds now hold through application lock-in and organisational inertia, more than through new victories.

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