Macromedia 8 screw-up

After installing Macromedia Studio 8, my extension manager doesn’t work. All my previously installed extensions are gone and does not allow me install any new ones. The error is - This require Macromedia 8 or greater insalled in your machine. So this extension will not be installed. But I have all the macromedia studio 8 installed in C:programmfiles. - Can someone tell me how to fix it please.