If your computer is running slowly or you are getting warnings about low disk space, the first thing to check is how much storage you have left. A nearly full drive causes noticeable slowdowns because Windows needs free space to manage temporary files, run updates and keep things running smoothly.
How to check your storage
Click the Start button and open Settings. Click on System, then click on Storage. You will see a bar showing how much space is used and how much is free on your main drive. Windows also breaks it down by category so you can see what is taking up the most space, such as apps, temporary files or documents.
How much free space do you need?
Aim to keep at least 10 to 15 percent of your drive free at all times. On a 256 GB drive that means keeping at least 25 to 40 GB available. If your storage bar is showing in red, your drive is critically low and you should free up space as soon as possible.
What to do if space is low
If your drive is almost full, click on Temporary files and let Windows show you what can be safely removed. Tick the boxes next to the items you are comfortable deleting, such as temporary files, thumbnails and delivery optimisation files. Do not delete anything you are unsure about. Click Remove files.
If that does not free up enough space, look at which apps are using the most storage and consider uninstalling anything you no longer use. Our guide on how to uninstall a program in Windows 11 walks you through this. For a full walkthrough on speeding things up, see our guide on how to free up space and speed up a slow computer.
Turn on Storage Sense
Windows has a built-in feature called Storage Sense that automatically cleans up temporary files and emptied recycle bin items. In the same Storage settings page, click Storage Sense and turn it on. You can configure how often it runs and what it cleans. This keeps your drive from filling up without you having to remember to do it manually.
When to get help
If your storage is critically low and you are not sure what is safe to delete, rather get someone to take a look before you remove anything important. Deleting the wrong files can cause problems that are harder to fix than a full drive.