Besides the start menu items, you will also have registry keys left over, as well as the item in your "Add or Remove Programs" dialog.
Best to run the installer of the demo again. If it tries to install, let it... uninstall afterwards. If it thinks you've already installed it, it will either:
1) let you uninstall
2) let you reinstall
3) Display an error and quit
In case 1, proceed. In case 2, proceed and uninstall afterwards. In case 3, you will need either:
1) Modify the registry yourself, remove the entries of that demo program
2) Try using the Add or Remove Programs dialog. Try to uninstall the demo program, and it *might* prompt you that the program is already gone and if you want to remove the entry. Say yes. If it doesn't prompt you that, you will have to use 1 - edit registry yourself.
All of the above depends on how the installer of that demo program is written.
Or, you could just don't care and let the registry entries hang around...
