For starters, did you allow the installer to drop the game in \Program Files (x86)\Final Fantasy VII, or did you change it? If you didn't change, uninstall and reinstall, this time overriding the default directory with something like \Games\Final Fantasy VII.
Next, if you've used the registry cleaning tools or manually mucked with your registry, it's a safe bet the game won't work at all. Re-run the converter program, and when (if?) it asks, choose "Overwrite." Make sure you include the quotation marks when prompted for the installation and movie paths. Once you've done that, nuke everything related to 7H and install clean using the links in the FAQ/Tutorial.
At this point, you should be good to go. If you get errors, stop (don't fumble around) and describe (or better yet, copy/paste) what you're seeing.