Ok, open up your run.bat you sdhould see this:
@echo off
java -Xmx300m Jframe 10 0 highmem members 32
pauseReplace that with:
@echo off
start javaw -Xmx300m Jframe 10 0 highmem members 32
exitSave and exit, and when your run the client there's no cmd! Congratulations, you got your own taste of basic programming!