How Do I Know Which Version of Windows I Have: Exact Build Check

You can find your Windows version in under 30 seconds: press Windows key + R, type winver, and press Enter. A dialog box opens showing the edition (Home, Pro), the version number (such as 24H2 or 23H2), and the OS build (such as 26100.xxxx). Keyboard-only option: press Windows key + Pause/Break, or open Settings > System > About and read the Windows specifications panel.

That dialog answers the question most people actually have. The confusion starts because Microsoft uses "version" to mean three different things, and tech articles often quote one when you asked about another. Windows 11, version 24H2, OS build 26100.1742, and edition "Windows 11 Home" are four separate labels produced by four separate systems. Knowing which label you are reading changes what the answer means.

Three version numbers and what generates each

The first label is the product line: Windows 10 or Windows 11. Microsoft determines it at install and fixes it to the license. A machine cannot "upgrade" from 10 to 11 without passing a hardware compatibility check, so the product name is also a hardware verdict.

The second label is the feature update codename, such as 24H2 or 23H2. Microsoft ships Windows as an annual feature update, and the codename encodes the year and half-year of release: 24H2 means the second half of 2024. Each feature update resets a support clock and introduces new platform capabilities. The current numbering scheme replaced the older Windows 10 pattern of 21H1, 21H2, and 22H2.

The third label is the OS build, printed as a five- or six-digit number. The number is not arbitrary. Build 26100 corresponds to Windows 11 24H2. Build 22631 corresponds to Windows 11 23H2. Build 22621 corresponds to 22H2. The last four digits after the dot are the revision number, which increments with each cumulative security update. Build 26100.1742 and 26100.2033 are the same feature version at different patch levels. This is the label Microsoft's support documentation uses, and the one worth quoting in any support ticket.

Underneath all of this sits the kernel version, which you can see in winver as "OS Build" but is also exposed through commands like systeminfo. Windows 11 kernels continue the NT 10.0 numbering inherited from Windows 10, which is why some diagnostic tools report Windows 11 as version 10.0. That mismatch is one of the most common support confusions.

The registry, WMI, and command-line pathways

The winver dialog reads from the registry key HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion. Under that key, the DisplayVersion value gives the feature codename, CurrentBuild gives the build number, UBR gives the update revision, and ProductName gives the product line. These are written by the servicing stack at install and update.

Command-line tools take different paths to the same data. Running winver.exe is the friendliest. Running systeminfo in Command Prompt pulls from WMI classes and produces a longer output where you look for "OS Name," "OS Version," and "OS Build Number." The PowerShell command Get-ComputerInfo returns the same fields and is useful for scripting a check across a fleet.

A counterintuitive detail: the ProductName registry value still reads "Windows 10 Pro" or "Windows 10 Home" on many Windows 11 machines. Microsoft kept the string unchanged to avoid breaking software that parses it. If a script greps ProductName to decide the product line, it will misreport Windows 11 as Windows 10. The reliable field for scripted checks is the build number, not the name.

Windows 10 versus 11: the compatibility threshold

Windows 11 requires specific hardware, and that hardware requirement is what separates the two product lines for most users. Microsoft's published requirements include a 64-bit processor on the supported list, TPM version 2.0, Secure Boot capability, at least 4 GB of RAM, and 64 GB of storage. The TPM 2.0 requirement is the one that most often fails on machines built before roughly 2017.

This threshold is why "which version" is not just a curiosity. A machine on Windows 10 that fails the TPM check cannot take a feature update to Windows 11. It will remain on Windows 10 for the life of that product, and Windows 10 reached end of support on October 14, 2025. Read together, those two facts mean the version check also tells you whether the machine is receiving security patches at all.

Windows 11 feature updates have their own support windows, and Microsoft documents them on the Windows release health page. A machine on 23H2 will stop receiving updates when that feature update reaches its end-of-servicing date, which is typically 24 months after release for Home and Pro editions. The version check tells you where the clock stands.

Reading the right label for the right job

Different tasks need different labels. Install a driver and the support page asks for the product line and sometimes the feature version. Report a bug to Microsoft support and the agent wants the full build number, including the revision. Check whether your machine is still patched and you need the revision alone. Check whether it can run a piece of software and the feature version is what the developer tested against.

The comparison makes one point clear: no single label answers every question, and quoting the wrong one wastes time. A support agent given "Windows 11" has almost no information. A support agent given "26100.1742" knows the product, the feature update, and the patch level from a six-digit string.

What the update timeline looks like

The version number is a snapshot in time. It changes with each cumulative update and each feature update. The table below shows a typical sequence for a Windows 11 machine through one release cycle, using approximate dates for illustration rather than dated measurements.

The pattern shows why two machines that look identical on the desktop can have different build numbers. One was set up in November and one in March, and the second received half a year of cumulative updates before you looked. Neither is wrong. The revision number simply reflects how long the machine has been patched.

For Windows 10, the timeline ended differently. The final feature update was 22H2, and the product exited support on October 14, 2025. A Windows 10 machine will not show a new feature version after that, but it may still show revision numbers on machines enrolled in Extended Security Updates, which Microsoft sells per machine per year as a stopgap for organizations that need more time. The price is published per machine and changes with the program's phases.

Misconceptions and red flags

Several beliefs about Windows version checking are technically wrong. One is that "winver shows everything." It shows the product, feature version, and build, but not the edition (Home, Pro, Enterprise, Education) or the activation state. Another is that the registry value ProductName reflects the product line. As noted above, it often does not. A third is that the build number tells you the exact patch level. Build 26100.1742 and 26100.2033 share the first five digits but represent different patch states.

Watch for these red flags when checking a version:

A build number that does not match the feature version it claims, which can indicate a tampered or pirated image. ProductName reading "Windows 10" on a machine you know was upgraded to Windows 11. A feature version older than the current supported release, which means the machine is out of servicing. Missing revision numbers, which suggests updates have been blocked or failed. An edition string that does not match the license you paid for, such as Enterprise appearing on a Home license.

The most common scam pattern is a caller claiming to be from Microsoft and asking you to read the build number to "verify" your license. No legitimate Microsoft support agent cold-calls a consumer to verify a version. The build number is public information, not a security secret, and sharing it does not compromise the machine.

Practical actions

The fastest checks, in order of effort: press Windows key + R, type winver, press Enter. Read the four lines. If you need to send the result to support, run winver from Command Prompt and screenshot the dialog.

For a scripted check across one or two machines, open PowerShell as administrator and run:

Get-ComputerInfo | Select-Object WindowsProductName, OsVersion, WindowsBuildLabEx

That returns the product line, the kernel version, and the full build string. For a fleet, loop the same command over a list of hostnames, or use the registry key directly: HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion, reading DisplayVersion, CurrentBuild, and UBR as separate values. Build the full build string as CurrentBuild.UBR.

To decide on an upgrade, check the product line first. If it is Windows 10, the machine is past end of support unless it is enrolled in Extended Security Updates, and the next step is to evaluate hardware against the Windows 11 requirements at Microsoft's Windows 11 specification page. If it is Windows 11 with a feature version more than 24 months old, the next step is to install the latest feature update through Windows Update. Set a reminder to recheck the version one month after any major update, because feature update rollouts are staged and your machine may receive the release later than the general population.

Threshold reconciliation: Windows 11's 24-month Home/Pro servicing window and the 36-month Enterprise/Education window are different thresholds for the same release. If you check a machine and the feature version is 22H2 on an Enterprise license, it is still supported; the same version on a Home license is not. The build number and the edition together determine the serviced state. Read both.

Limits of the check

The version number tells you what is installed, not what is working. A machine can report build 26100.2033 and still have a failed cumulative update if the update installed partially. A machine can report the current build and still have outdated drivers, third-party software, or a disabled security feature. The check is a starting point for support, not a diagnosis of system health.

The version number also does not tell you whether your machine is compatible with Windows 11 if it still shows Windows 10. Compatibility requires running the PC Health Check tool, which tests the specific hardware against the published list rather than reading a registry string. The build number can confirm the current state; it cannot predict the upgrade.

Finally, the build string is only as accurate as the last successful update. On machines where updates are paused, blocked, or managed by an IT department, the displayed version may lag the release channel by weeks or months. Verify against your organization's update policy before assuming the reported build reflects the intended patch level. For a single-check answer, winver remains the fastest and most reliable source, and it is the string to quote whenever you ask for help.