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This is part of the safety mechanism in case the upgrade process goes wrong.

If the installation fails, the system can use the “Windows.old” folder to undo the changes.

Windows 10 delete Windows.old folder

Windows 10 delete Windows.old folder

Windows 10 Storage Sense

Delete previous version of Windows

Temporary files

Previous Windows Installation

File Explorer open drive properties

Open Disk Cleanup

Cleanup system files

Disk Cleanup delete Windows.old

Windows 11 clean install

Surface Laptop Studio 2 photos

Windows 10 to 11 upgrade preparation

Windows 11 new PC install

Windows 10 mount drive on empty folder

Windows 10 backup

Windows 10 Find My Device

Outlook Client Hero

Windows 10 Start menu on HP ZBook Studio G4

Former Microsoft Executive Vice President Terry Myerson stands in front of a presentation about Windows 10

Surface Hub 2S

Windows Insider program settings

Xbox controller with WD-40

Elden Ring Nightreign

MSI Claw surrounded by Steam Deck, ROG Ally, ROG Ally X, Nintendo Switch, Legion Go S, and Legion Go.

The rare Caine Trailblazer operator skin, obtainable from the Return to Verdansk event in Call of Duty: Warzone

Dune: Awakening

DOOM: The Dark Ages