If you maintain software that must run on Windows 7 but demands high-accuracy timestamps, deploying KB2670838 is no longer optional—it’s a . Conversely, if you control the target environment, update your systems and enjoy Windows 8+ level precision on Windows 7.
If you're developing software that needs to support Windows 7, or if you're a user encountering this error, here are proven solutions:
The iperf3 community has addressed this by:
For greenfield development, targeting Windows 10 or Windows 11 eliminates these compatibility concerns entirely – GetSystemTimePreciseAsFileTime is always available with full precision. getsystemtimepreciseasfiletime windows 7 upd
If your software calls this function directly, it will fail to launch on any Windows 7 machine, regardless of how many updates are installed. The Workaround: How to Support Windows 7
The frequent appearance of this function in "Windows 7 update" discussions usually refers to application crashes rather than a system update you need to install. Why You See This Error on Windows 7
Article last updated: October 2025 – reflects Windows 7 extended support (ESU) status and confirmed update availability. If you maintain software that must run on
The function GetSystemTimePreciseAsFileTime is not available on Windows 7; it was first introduced in . Because Windows 7 has reached its official end of life, Microsoft has not released an update to backport this specific function. Understanding the Compatibility Gap
iperf3, a popular network performance measurement tool, began using GetSystemTimePreciseAsFileTime in version 3.17.1. When Windows 7 users attempt to run this version, they encounter the missing entry point error. The impact is severe: without the high-precision time function, network test accuracy degrades from microsecond-level to second-level, rendering the tool ineffective for precise throughput measurements.
Subject to CPU frequency scaling drift on older hardware. Need to recalibrate periodically. If your software calls this function directly, it
: Developers using the latest versions of Visual Studio (v145 toolset) or Qt have dropped Windows 7 support.
The most successful way to force apps requiring this function to execute on Windows 7 is by using an open-source compatibility layer called VxKex on GitHub.
Before deploying software to Windows 7 systems, verify compatibility: