Why is my computer showing a warning message about a low disk space when I have plenty of free storage?

1. Check Windows Disk Cleanup to delete unnecessary files and recycle bin.
2. Check for specific applications which are huge and consider deleting or archiving them.
3. Check for large temporary files (CTRL+ALT+DEL > Task Manager > Processes > View Downloaded Files).
4. Consider disabling hibernation or system restore.
5. Check the Program Folder for unnecessary files that have not been uninstalled or deleted.