[Haskell-cafe] very elementary "import" problem .. help

Hello, import System.Posix --import Network import System.Process --import Directory import STM I am loading the above script in ghci. However, System.Posix, System.Processand STM cannot be found. Network and Directory are found. I assume when ghc is installed on Windows that the Windows registry get populated with paths to GHC 'library" directory paths. Please someone tell me why I am having trouble importing these modules/libraries. Kind regards, vasya