1. Review Storage settings
Windows 11 groups storage by apps, temporary files, documents, pictures, videos, and other categories. Start here because it shows the largest categories without third-party software.
2. Clean temporary files
Select temporary files, thumbnails, delivery optimization files, and Recycle Bin only after reviewing each checkbox. Downloads should stay unchecked unless you already backed up the folder.
3. Sort apps by size
Open installed apps and sort by size. Games, creative tools, virtual machines, and phone backup tools are common reasons the C drive fills up.
4. Turn on Storage Sense carefully
Storage Sense can automatically remove temporary files and cloud-backed local files. See the dedicated Storage Sense guide before enabling Downloads cleanup.
5. Use a disk analyzer when space is still missing
If Windows categories do not explain the usage, a disk analyzer can show hidden large folders. Compare options in the disk space analyzer guide.