Changing path of install

Hello,
Currently I have a separate partition on which I install most games. I intend to replace the C drive with an SSD and to get the most out of it I suppose I should have all the sceneries and such installed on the system (C) drive. Anyone know how this can be done whithout having to re-install the game from scratch? There shoud be a path somewhere pointing to the drive, couldn't find it in any .cfg file so I suppose it must be in the registry?