right click on run.bat and click modify
and replace all with this :
@echo off
title Client
cd bin
"YOURFJAVAPATH" -Xmx300m client 10 0 highmem members 32
pause
replace YOURJAVAPATH with the map to your java , it should look like this
@echo off
title Client
cd bin
"C:\Program Files (x86)\Java\jre6\bin\java" -Xmx300m client 10 0 highmem members 32
pause