You have not said what Operating System you have but on the assumption it is Windows, please try the following:
[If It is not Windows, please give your system details.]
Completely remove all traces of Java and Frostwire. To do this use Revo Uninstaller
or a similar program since Windows uninstaller fails to do the job thoroughly.
Before doing this ensure you have a back up of the files in your save and shared folders, or at least remove them to your desktop or somewhere similar, just to be on the safe side.
Then install Java from HERE
using the offline installer and finally Frostwire from the FrostWire.com link above