Hi SR,
Your description suggests there are some fundamental installation issues with the Office installations that need to be resolved. Did you install Office 2007 first? When using multiple Office versions, always start with the oldest, installing each newer version in order until you've installed the newest.
Even so, since you're unable to manage the installations via the Windows Control Panel, I suspect you'll need to kill both installations and start over. To do this, see:
http://support.microsoft.com/kb/928218
and
http://support.microsoft.com/kb/290301