:define here the location of your java environment
set JAVA_HOME="C:\Program Files (x86)\Java\jdk1.6.0_18\"

if exist s2s.jar_tmp GOTO Update

%JAVA_HOME%bin\java -Xms500M -Xmx500M -jar s2s.jar start

exit

:Update

%JAVA_HOME%bin\java -jar updater.jar