Hey there,
to me it sounds like the Java installation is not proceeding correctly.
I suppose you are trying an online installation package.
Check if the Win 8 firewall is allowing the installer to download the needed files.
Turn off the firewall temporarily!
Worst case would be that there is an elder Java version concurring or a partial installation.
If that is the case you will have to uninstall this installation and clean the PC/Registry from any leftovers.
look here:
http://www.java.com/en/download/faq/remove_olderversions.xml
You can also try an offline Java Installation package
look here:
http://www.java.com/en/download/help/win…ne_download.xml
I don't know if there is any Win8 specific problem!
have fun...
Dani