You can't delete them as they are system folders, and they will be recreated upon next boot/login.
You CAN hide them though (assuming you don't have "show hidden files" enabled in Explorer), by simply applying the "hidden" file attribute to them.
To do this:
- Right-click the folder you want hidden, pick Properties, check-mark "Hidden", and hit OK.
or
- Open a command prompt, then use
attrib
to hide them. E.G.:attrib c:\users\YourName\Favorites +h