Try redownloading it - if that does not fix it, can you do the following please:
run the command "cmd" to open the command prompt [you can open the RUN dialog with WIN+R]
then type java -version and hit enter
Does it say something like "(build 1.8.0_....) in the first line? if not, I recommend you update your java to Java 8 - if you cannot do this, please report back, I will export it for java 7 then - please make sure that you have at least java 7 running though (1.7.0)