try using quotes in your command line, like this, for example:
copy c:\sourceFOLDER\"large folder or file to be copied" c:\experimentFOLDER\destinationFOLDER
If the folder or file you are copying has spaces in it's name, like this: Large Folder or File, you'll have to use quotes around it to tell the computer to recognize it as ONE object
If there are folders inside the directory you wish to copy from, you will have to use the XCOPY command and add the /s switch to the end of the command line, like this: xcopy c:\sourceFolder\"large folder to be
copied" c:\experimentFolder\destinationFolder /s
If there are a LOT of files an folders to be copied, give it a few minutes to complete after you enter the command and press ENTER