You want to make a command that targets a specified path, but it includes a space on a file.
You want to make a copy from one directory to another:
copy c:\File to be copied\ e:\backup folder\
You get the following message: The specified file is not found.
It's very simple, just put quotation marks around the folder with space or more, like this:
copy c:\"File to be copied"\ e:\"backup folder"\
The easiest way to avoid this kind of message is to use the underscore "_"
instead of space when naming your files and folders.