[Haskell-beginners] More than one GHC version installed

Hi. I'd like to know if it is possible to have a separate install directory with GHC 7.0.4 and another with GHC 7.2.1 in the same Windows system. I was thinking about having a standard PATH environment "C:\Haskell\ghc\bin". Then have a folder structure like "C:\Haskell\ghc-{7.2.1, 7.0.4}", renaming either one of them into "C:\Haskell\ghc" depending on what I would like to be using. I have taken into consideration to renaming the cabal install directory in the same manner. However, the problem with this approach is that the package database remains somewhere I can't find. Does the default GHC store the package database in the registry or something? I'd appreciate if you could hint me where I could swap the databases for this setup.