MySql Service Was Gone Even Though I Didn't uninstall it ?

Recently I couldn't see my MySql in the Service List on Windows 7, also in the MYSql Folder, everything was deleted except for the installer even though I have never uninstalled it. When I tied to run the installer to run the service again, it said the server has already been installed and there is no additional product needs to be installed but I can't see MySql on the service. Does this mean I lost all of my data ? if I'm not mistaken long time ago even after uninstall and reinstalled of MySql, the tables and other information were still there. Anyway, what should I do now to show the service back ?