Windows Update installs but reboots endlessly (update rollback loop)

The problem: After installing updates, the device enters an endless reboot/rollback loop and won't reach desktop normally.

Symptoms: Repeated 'Working on updates' then reboot; automatic repair; update rollback; cannot complete update.

Likely cause: Failed servicing transaction, driver incompatibility, or disk corruption.

Category: Windows Update · Difficulty: Advanced · Windows: Both

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