Windows

System folders, repair tools and security features of Windows 10 and 11.

20 Articles

Built-in tools

Device ManagerHow to use Device Manager to find devices without drivers, read error codes, update, roll back or uninstall a driver.
Disk Cleanup (cleanmgr)What the classic Disk Cleanup tool removes, what 'Clean up system files' adds, and how to run cleanmgr from the command line.
Event ViewerHow to read Windows event logs in Event Viewer, which logs matter for crashes and errors, and how to export or clear them.
Task SchedulerWhat Windows Task Scheduler does, where tasks live, and how to view, disable or remove a task safely.

DISM (Deployment Image Servicing and Management)What DISM is, the /CheckHealth, /ScanHealth and /RestoreHealth commands, and how DISM and SFC work together to repair Windows.
SFC (System File Checker)What sfc /scannow does, how to read its results, where the CBS.log is and when to run DISM first.

BitLocker recovery keyWhat the BitLocker recovery key is, why Windows asks for it, where to find it and how to check protection with manage-bde.

Microsoft Defender SmartScreenWhat SmartScreen is, why it shows 'Windows protected your PC' for new downloads, and how to check a file before running it.
Storage SenseWhat Storage Sense does in Windows 10 and 11, which files it removes, and how to configure it safely.
System RestoreWhat System Restore and restore points do, what they do not touch, and how to create a restore point or go back to one.
Windows Recovery Environment (WinRE)What WinRE is, how to open it, what tools it offers, and how to check it with reagentc /info.

Startup appsWhere Windows lists the programs that start with it, what the startup impact means, and how to turn startup apps off safely.

Microsoft Defender AntivirusWhat the antivirus built into Windows does, how to run quick, full and offline scans, and how it works with other antivirus programs.

hiberfil.sys (hibernation file)What hiberfil.sys is, why it is so large, how Fast Startup uses it, and how to shrink or remove it with powercfg.
pagefile.sys (page file)What the Windows page file does, why it should not be removed, and how its size is managed.

Driver Store (DriverStore\FileRepository)What the Windows Driver Store is, why it grows, and how to list and remove old driver packages safely with pnputil.
Temporary files in WindowsWhere Windows keeps temporary files (%TEMP%, C:\Windows\Temp), what is safe to delete and the supported ways to clean them.
Windows Update cache (SoftwareDistribution)What the SoftwareDistribution folder holds, why Windows Update files take space, and how to clean or reset the update cache safely.
Windows.old folderWhat the Windows.old folder is, why it appears after an upgrade, how long Windows keeps it and how to remove it safely.
WinSxS folder (component store)What C:\Windows\WinSxS is, why Explorer overstates its size, and how to shrink it only with supported DISM commands.