KB5089573, the May 26, 2026 optional preview for Windows 11, ships the new Low Latency Profile (faster Start menu, Search, and app launches). On older or unsupported-for-24H2 hardware it fails install with 0x800f0915 or 0x80070306.

Both errors trace back to servicing stack pressure. 0x80070306 is the same EFI partition headroom problem we covered for KB5089549. 0x800f0915 points at component store corruption or a missing servicing prerequisite. This is an optional preview, so skipping is a valid answer.

When to Install KB5089573

Worth the install on mid-range business laptops where you want a snappier feel, recent Surface and ThinkPad Gen 4 or newer, and any bench machine you use for compatibility testing. Hold off on mission-critical workstations until next month's GA cumulative, anything older than 2020 silicon, machines with under 200 MB free on the EFI System Partition, and anything servicing users (domain controllers, RDS hosts, terminal servers).

Fix 0x80070306

Check EFI free space first. Same playbook as the KB5089549 EFI bug.

mountvol Z: /S
Get-PSDrive Z | Select-Object Used, Free
mountvol Z: /D

Under 200 MB free and you have the same root cause. Expand the ESP before retrying.

Fix 0x800f0915

Run the servicing stack repair sequence:

DISM /Online /Cleanup-Image /CheckHealth
DISM /Online /Cleanup-Image /ScanHealth
DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow

Reboot, then retry the update. If DISM also fails, you are missing a source. Mount a current Windows 11 ISO and point DISM at it:

DISM /Online /Cleanup-Image /RestoreHealth /Source:WIM:D:\sources\install.wim:1 /LimitAccess

Replace D: with the mounted ISO drive letter.

Clean Boot Attempt

If the update still fails after DISM, a stuck service or third-party AV filter driver is usually blocking. Disable non-Microsoft services via msconfig, reboot, retry the install, then re-enable everything. Faster than chasing the specific service.

Rollback

Already installed and seeing regressions? Uninstall and pause updates for a week.

wusa /uninstall /kb:5089573

Want help deciding which Windows preview updates to stage versus skip on your fleet? Rain City Techworks handles managed IT and security for businesses in the Seattle and Tacoma area.