i am getting an unexpected error on this command

ERASE c:\mydirirectory\myfile.zip

code 1705 file access is denied
You have attempted to write to a file that is write-protected or open exclusively by another.

In fact the file is not opened or currently being accessed.
if i go to file properties the file is read only - if i de-select this quality the file is erased

Is there a way i can bypass the error and erase the file or maybe change the property of the file to allow erase

thanks

k .