java can run jar from cmd but not by double clicking

Question

I just created a jar file using jdk7. I tried running it but kept getting an error. It turned out it was pointing at a jre6 and not the jre in jdk7. So, I used the following

Answer 1

Check if the file type jarfile is actually registered with the *.jar extension using

assoc .jar

Seems like .jar is not linked to jarfile.