# Windows · Rain Wiki

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

- [BitLocker recovery key](https://raincleaner.eu/wiki/windows/bitlocker-recovery-key): What the BitLocker recovery key is, why Windows asks for it, where to find it and how to check protection with manage-bde.
- [DISM (Deployment Image Servicing and Management)](https://raincleaner.eu/wiki/windows/dism): What DISM is, the /CheckHealth, /ScanHealth and /RestoreHealth commands, and how DISM and SFC work together to repair Windows.
- [Driver Store (DriverStore\FileRepository)](https://raincleaner.eu/wiki/windows/driver-store): What the Windows Driver Store is, why it grows, and how to list and remove old driver packages safely with pnputil.
- [Microsoft Defender SmartScreen](https://raincleaner.eu/wiki/windows/smartscreen): What SmartScreen is, why it shows 'Windows protected your PC' for new downloads, and how to check a file before running it.
- [SFC (System File Checker)](https://raincleaner.eu/wiki/windows/sfc): What sfc /scannow does, how to read its results, where the CBS.log is and when to run DISM first.
- [Storage Sense](https://raincleaner.eu/wiki/windows/storage-sense): What Storage Sense does in Windows 10 and 11, which files it removes, and how to configure it safely.
- [Temporary files in Windows](https://raincleaner.eu/wiki/windows/temp-files): Where Windows keeps temporary files (%TEMP%, C:\Windows\Temp), what is safe to delete and the supported ways to clean them.
- [Windows Recovery Environment (WinRE)](https://raincleaner.eu/wiki/windows/winre): What WinRE is, how to open it, what tools it offers, and how to check it with reagentc /info.
- [Windows.old folder](https://raincleaner.eu/wiki/windows/windows-old): What 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)](https://raincleaner.eu/wiki/windows/winsxs): What C:\Windows\WinSxS is, why Explorer overstates its size, and how to shrink it only with supported DISM commands.