Installing CFMX7 over CFMX6 will certainly have killed your
cfmx6 installation. I would uninstall and delete the directory.
Reinstall cfmx6.x as it was before. If necessary there is a
technote on the support site that tells you how to manually
uninstall deleting directories and updating your registry.
If you choose the defaults when you install CFMX7, it will
co-exist with cfmx6.x. CFMX6 installs by default to c:\cfusionmx
and cfmx7 installs to c:\cfusionmx7. Also, cfmx7 will increment the
ports it uses to allow it to run with cfmx6.
Before you delete/uninstall confirm that you do not have a
cfusionmx7 directory. If it is there, perhaps you just clobbered
your connection to the webserver and CFIDE. You should install
cfmx7 to use its internal webserver so it can co-exist with
cfmx6