By that you should be able to decide on yourself which folder contains important or useless data. Examples of folders containing useless data of considerable size: Why are there directories called local, locallow, and roaming under \users\\appdata?

The original user's profile directory lives in a directory like c:\users\username\appdata. How can i refer to the current user's profile directory when using the windows command line? User profiles are stored in user data directory and it vary depending on the operating system. The easiest way is to navigate to chrome://version and look for the profile path field.