How to delete the Windows.old folder after reinstalling Win7? What can I do if Windows.old cannot be deleted?

When reinstalling Win7, if you have not formatted the system disk, the previous system files will be loaded into the Windows
.old folder. However, if you want to delete this folder, you will find that it can't be deleted. The prompt "Can't find the item", "The operation is rejected by the system" and so on. So how can I delete the Windows
.old folder? The method is as follows: Open “Computer”, right click on the partition where the system is located, select “Properties →Disk Cleanup", the Disk Cleanup Tool will start scanning the files that can be cleaned up in the drive letter, and then the files that can be deleted will be displayed. List, in which you can see the "previous Windows installation" and the size of the space it occupies, the "description" in the description below is clearly described in the folder named Windows.old, here, you can put in the list Temporary files, error report files, and other useless files are selected together, and then click “OK”. After confirmation, the system will ask whether to permanently delete the selected file, select “ delete file & rdquo; after the disk cleaning tool starts cleaning the selected file, after a few seconds to a few minutes (length depends on the file size), Windows.old file The folder and the files selected by the user will be completely deleted. The selected file will not be deleted to "Recycle Bin", but will be permanently deleted, so be sure to check carefully if it is a file that needs to be deleted before confirming the deletion.