If you can restore back to a point before you tried to install Disk-keeper 8.0, that should solve it. Otherwise, you could try this:
Uninstall Diskeeper lite
Reininstall Diskeeper 8.0
Unintstall Diskeeper 8.0
Reinstall Diskeeper Lite.
Maybe Diskeeper 8.0 has left some registry entries that are confusing Diskeeper lite. Just a guess.