How can I fix Windows Update error 0x801901f7 on newly imaged PCs?

Check the Windows Update logs for HTTP 503 responses. That points to a service being unavailable, though it does not establish which Microsoft incident is responsible. If several different models are failing at the same time, a service-side problem is worth considering before rebuilding the images.

Check Microsoft service health for relevant incidents and retry later. The reported Azure and Microsoft 365 issues may be related, but the error alone does not prove it.

Try the Windows Update troubleshooter, but don't treat the error disappearing as proof that updates are working. The update check can still return no updates while the underlying service is having trouble. Run another check and confirm that expected updates actually appear or install.

Check whether the Microsoft Update Catalog and Microsoft Store are also having trouble. Reports included 503 errors from the catalog and Store updates failing around the same time. Those symptoms can help distinguish a broader service problem from something specific to your image, although they won't prove the cause on their own.