In addition to changing the System Protection disk usage limit to reduce the amount allocated and free up disk space, you can immediately delete and recover almost all of the disk space used by System Restore and hidden copies (including previous versions) by using the Disk Cleanup Manager to eliminate everything but the last system recovery point. Windows system protection can take up to 10% or more disk space to back up system restore points and older versions. Update: Stop getting error messages and slow down your system with our optimization tool. Delete one or more restore points using PowerShell.Delete all restore points in Windows 10.Delete all but the last restore point of the system.