Modern Standby: The Feature That Breaks Sleep Completely

This is a Modern Standby laptop that either wakes immediately or never remains in a low-power state, so identify the wake source rather than trying registry changes. Run powercfg /a in an elevated Command Prompt to confirm the sleep model, then run powercfg /sleepstudy /output C:\Temp\sleepstudy.html after several failed sleep sessions. Open the report and note the top offender or exit reason; immediately after an unwanted wake, also run powercfg /lastwake. Update the BIOS or UEFI, chipset, Wi-Fi, graphics, and storage drivers from the laptop manufacturer, then retest with external USB devices disconnected. Only disable wake capability for the device or task shown by the report; broadly disabling services creates new problems. Modern Standby is a platform design choice, so Windows generally cannot be converted reliably to traditional S3 sleep with a generic tweak. If SleepStudy identifies firmware or a driver repeatedly, send that report to the device maker.