With the command windows open and if the desired directory/folder appears after the prompy character, type
del <filename> then press enter
where <filename is the name of the file to be deleted.
This command will fail if the file is set as read only.
To force deletion even if it set as read only
type
del /f <filename> then press enter
Type
exit or mouse click on the red x to close the command window.
Tom Ferguson