I have a feeling this might be a Java problem, but it is only a guess.
Please could you ensure Frostwire is fully closed then,
completely remove all traces of Java. To do this use Revo Uninstaller
or a similar program since Windows uninstaller in the Control Panel fails to do the job thoroughly. Revo will locate additional related files which need to be removed.
Then install Java from HERE
using the offline installer.
Please let us know if this helps or not.