Hi and Welcome to the Gnutella Forums. From that error message it seems that there is an older version of LimeWire or parts of a previous copy of LimeWire on your computer. You should run the uninstaller of LimeWire or search your computer for "LimeWire" and delete anything that has to do with it. Next run the installation again and if it does not work, you could run Windows Update to make sure you have the latest version of Windows. I hope this helps.