Please, answer this question for a dummy: I can see the different directories in a given POSITION, but once I type cd some directory I get :" the system can not find the specified route"... some time: "the system can not find specified FILE"
Thanks a LOT in advance!Your question isn't clear but use double quotes around the path, or path and filename.

For a folder:

cd "my folder"

cd /d "e:\books\my author"

To launch a file:

"c:\my folder\vt.exe"

Thanks for your answer. I am going try be clear on my question. Please be patience.
I have this picture on the ms-dos screen:
C:\users\public\documents>
Typing “dir” and enter I can see a file : 12.503 The Fed is joining forces with the big… (it is a .docx)
I would like change this file name, then I write : rename space and that long title…. Two answers: the system can not find the specified file
The SINTAXIS of the command is not correct
I thnk is not fair have a wierd name for that file , (I see several ones like that), then I have tried to change its name, also I have tried to see ist content using “type” command, but  I can have had success anyway.
I appreciate your comments. Thanks, and have a very nice rest of the day!
Have you tried using quotes as foxidrive mentioned?

Thanks again! I have used quotes and it works!. I mean I can get the file, but looking for it content I only get a lot of wierd signs...I was looking at ASCII table but I could not find all of them...can you help me?
Nice dayA plain text file has only the text you see,
while a DOC and docx file has invisible formatting and container characters at the start and throughout the file, along with the text that you see.

That is why when you type many files that you see odd characters, and don't always see all the file, sometimes also hearing a beep.

Basically there are plain text files and there are binary format files, and the binary format files will also contain all sorts of odd characters above ascii value 127 and below ascii value 32 amongst the regular keyboard characters.  See http://www.asciitable.com/

A useful type of program is a Hex Editor and viewer - which will open any file and show you the ascii characters and HEX values for each character, from 00 to FF in a table. 
With a program like this (WinHex is a free one) you can see the makeup of files including invisible characters that you don't usually see.