Horizontal line artifacts on the taskbar area of the built-in display after KB5126657 (Surface Pro 5th Gen, Windows 10 22H2)

Question

Horizontal line artifacts on the taskbar area of the built-in display after KB5126657 (Surface Pro 5th Gen, Windows 10 22H2)

성욱 태 0

Screenshot of the taskbar (clean, no lines)

After installing the October 2026 cumulative update KB5126657 (Windows 10 22H2, build 19045.7807, installed 2026-10-15 09:43), thin horizontal lines appear across the taskbar area at the bottom of the built-in display on my Surface Pro (5th Gen, Intel Iris Plus Graphics 640). The lower parts of the taskbar icons look smeared. I attached two images: a normal screenshot (clean) and a photo of the screen (lines visible).

What I verified:

Screenshots (Snipping Tool / Win+Shift+S) look clean, so the lines are not in the composed desktop image. A photo of the screen shows them.

The lines are time-dependent: right after a fresh boot there are no lines, and they start to appear after roughly 4 hours of uptime and then stay.

The lines are not visible in screenshots, and not visible in the Surface UEFI screen. Note that I could only check UEFI right after power-on, when the lines are not present yet, so this does not rule out a thermal or hardware cause.

Win+Ctrl+Shift+B (graphics driver restart) did not remove the lines (they looked slightly lighter afterwards).

No new display driver was installed by Windows Update recently. The Intel display driver is 27.20.100.8682, the same package as before the update.

The external monitor (1920x1080, second display) shows no lines. The built-in display runs at 200% scaling, the external monitor at 100%.

Other updates installed around the same time: KB5131595 (Recovery Environment, 2026-10-14), KB890830 (MSRT, 2026-10-14), KB5128925 (.NET Framework, 2026-10-15).

Expected: clean taskbar rendering as before the update.

Actual: horizontal line artifacts at the bottom taskbar area of the built-in display.

Symptom pattern: in my experience this symptom appears after Windows updates are installed. This time it started after the October cumulative update (KB5126657), and then only after several hours of uptime.

Questions: Is this a known issue with KB5126657 on Surface Pro 5th Gen? Is there a fix or a recommended driver/firmware package, or should I uninstall the update?

Since the lines only appear after about 4 hours of uptime, could this also be a thermal or power-management issue rather than only the update?

Photo of the screen with the lines visible (taken with a phone):

Phone photo of the built-in display showing the horizontal lines at the taskbar

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Answer 1

Hi 성욱 태,

The fact that the horizontal lines do not appear in software screenshots and only affect the built-in display confirms this is a hardware issue rather than a software bug caused by the KB5126657 update. What you are experiencing is a known hardware defect common in Surface Pro 4 and Surface Pro 5th Gen devices, often related to thermal display degradation.

Why this is hardware, not the update:

Clean Screenshots: Since the Snipping Tool captures a perfect image, the Intel Iris Plus Graphics 640 is rendering the desktop flawlessly. The corruption occurs on the physical LCD panel itself.

Thermal Dependency: The artifact appearing only after roughly 4 hours of uptime strongly points to heat accumulation. As the internal components heat up, the thermal expansion affects the display panel's hardware connections or timing controller.

External Monitor Isolation: The external monitor showing no lines further proves the graphics driver (version 27.20.100.8682) and the GPU are functioning properly.

The Windows Update Coincidence: You noted that this symptom often appears after Windows updates. Installing cumulative updates is a resource-intensive process that pushes the CPU and SSD for extended periods, generating significantly more internal heat than normal usage. This sudden thermal load triggers the physical hardware flaw, making it seem like a software bug. Uninstalling KB5126657 will not permanently resolve the issue.

Recommendations and Workarounds:

Thermal Mitigation: Aim a small external desk fan at the back of the Surface Pro chassis to keep the internal temperature down. This can often delay or temporarily prevent the lines from appearing during long sessions.

External Display: Continue relying on your external monitor for extended working sessions.
Hardware Repair: Because this is a physical degradation of the display assembly, there is no recommended driver or firmware package that can fix it. The only permanent resolution is a hardware screen replacement or a device upgrade.