You should be typing
If you are still getting it as an unknown path, first try navigating to that path using explorer, if it doesn't come up then the folder doesn't exist anymore.
If you are able to find the folder with explorer, look in the address bar, and double check the path with what you are typing into the command prompt. (it has to match exactly)
Sometimes you have to navigate the command prompt all the way back to the root of the C:\ first by typing
until the prompt just says C:\
So basically, if you are getting the unknown path error, you are typing something wrong.
This may also be helpful for you:
http://androidforums.com/faqs/443072-adb-guide-updated-12-05-2011-a.html