Open Settings
Go to System
Click Storage
Review storage categories
Open Apps and features
Sort apps by size
Open File Explorer
Check Downloads folder
Check Desktop folder
Check Videos folder
Check Pictures folder
Check Documents folder
Empty Recycle Bin
Use Disk Cleanup
Use Storage Sense
Check OneDrive or cloud sync folders
Search for large files
Check temporary files
Check browser cache
Check game libraries
Check virtual machine files
Check backup files