Evo ti opcije koja će to sigurno riješiti:
Type:CMD in the search and hit Ctrl+Shift+Enter to open Command Prompt as administrator;
Click Yes when UAC dialog shows up;
Type: RD /S /Q %SystemDrive%\windows.old in the Command Prompt and hit Enter.
Then Windows.old folder will be deleted in Windows 10 without any obstacles. One thing that you should note is that do remember to launch Command Prompt as administrator.
Koji luck imam lol