Have you tried uninstalling GE via the 'Programs and Features' applet? Do it if not, & try reinstalling GE afresh.
Did you download the GE updater setup file or the full install file?
If you're still having problems installing it, download & run the Windows Installer CleanUp Utility click here (it apparently works for Win7 as well click here). Then try installing reinstalling from the full version. Available from under Installing at click here. G