How to see what's taking up space on your PC (Windows 11 and 10)
Start with Settings → System → Storage for a category breakdown. For folder-by-folder detail, use a disk space map tool like Roomy, WinDirStat or WizTree. Don't forget hidden hogs: hibernation, restore points and virtual disks.
Windows' "Other" and "System & reserved" categories are famously unhelpful. Here's how to see where your space actually went.
1. The built-in Storage page
Open Settings → System → Storage. Windows shows a breakdown by category; click Show more categories to see everything. Clicking a category, like Apps & features or Other, takes you to the details.
2. A folder-by-folder map
File Explorer can't sort folders by size, so a disk map tool is the fastest way to find a 40 GB surprise. Roomy has a built-in Space map: pick a drive, then click down through folders to see what's biggest, plus a list of the largest single files on your PC. WinDirStat and WizTree are other good free options.
3. Hidden space hogs to check
Hibernation file (hiberfil.sys)
Usually 40% of your RAM. If you never use Hibernate, you can turn it off from an admin terminal with powercfg /h off. This also disables Fast Startup.
System Restore points
Search for Create a restore point, select your C: drive, click Configure, and lower the max usage or delete old points.
WinSxS (component store)
It looks huge, but much of it is shared with System32. Never delete it by hand; run DISM /Online /Cleanup-Image /StartComponentCleanup instead.
WSL and Docker virtual disks
If you use WSL or Docker Desktop, their .vhdx files in AppData\Local grow and never shrink by themselves. Prune unused images with docker system prune, then compact the disk.
Game libraries
Steam, Epic and Xbox games often live under Program Files (x86) or XboxGames and are the largest folders on most gaming PCs.