Uninstalling VFP 9.0 does not remove VFP settings stored in the registry or any files that have been added to installation after the fact.
To completely uninstall VFP 9.0

1. Launch VFP and note directories returned by HOME() and HOME(7) functions
2. Uninstall VFP
3. Delete directories from step 1
4. delete registry key HKEY_CURRENT_USER\Software\Microsoft\VisualFoxPro\9.0

Keep in mind that it will delete all previous VFP settings. You may want to make backup before doing that if you want to restore settings later.