How to free up disk space in Windows 11

First, see how much space you have

Select File Explorer from the taskbar, then This PC on the left. The free space on each drive is shown under Devices and drives. In Settings > System > Storage, the bar for your drive turns red when space is low.

Steps

1. Turn on Storage Sense. Select Start > Settings > System > Storage and set Storage Sense to On. With its default settings it runs when the computer is low on space and removes temporary files you don't need.
2. Run it now. Select Storage Sense, then Run Storage Sense now.
3. Check what Storage Sense is allowed to delete. On the same page you can choose how long files stay in the Recycle Bin, and whether files in your Downloads folder are ever removed. By default, Downloads is not touched.
4. Use Cleanup recommendations. Select Start > Settings > System > Storage > Cleanup recommendations. Look through Temporary files, Large or unused files, Files synced to the cloud and Unused apps. Tick what you want removed and select Clean up in each section. Windows shows how much space each choice frees.
5. Find your biggest personal files. In File Explorer, open Videos, Pictures, Music and Downloads: these usually hold the largest files. Select View > Details, then right-click an empty area and choose Sort by > Size.
6. Move files you want to keep to an external drive. Connect a USB drive, select the files, choose Cut, open the external drive and choose Paste. You can still open them when the drive is connected.
7. Empty the Recycle Bin. Deleted files keep using space until the Recycle Bin is emptied.

One warning from Microsoft

If you upgraded Windows in the last 10 days, your previous version of Windows appears in the list as a system file you can delete. Deleting it frees a lot of space, but it can't be undone and you will no longer be able to go back to the previous version.

If that didn't work

Storage Sense only cleans the drive Windows is installed on, usually C:. For other drives, go to Settings > System > Storage > Advanced storage settings > Storage used on other drives. If Windows still says there isn't enough room to install an update, Microsoft's page explains how to use an external storage device to complete the update.