Find out which big files taking up disk space on Windows 10

• Open the File Explorer.
• Select the drive you want to check.
• In the Search input box, enter size:. A list of size options is dropped down, from Empty, Tiny to Gigantic.
• Select "Gigantic".
• Click on the menu "View" and select "Details".
• Click on the "Size" column to sort the search result in descending order.