Check what uses space

Open Settings → System → Storage. Wait while Windows calculates the categories. Review large categories such as Apps, Temporary files, and Documents.

Remove temporary files

Choose Temporary files, carefully review the list, then remove items you recognize. Be cautious with Downloads because it may contain files you want to keep.

Uninstall unused apps

Open Installed apps, sort by size, and uninstall only programs you know you no longer use. Back up important files before major cleanup.