I just spent considerable time trying to launch scala in a windows 7 x64 environment. The problem and solution are here: http://stackoverflow.com/questions/430376/batch-files-vista-x64-if-and-parenthesis
Basically, SCALA_HOME is C:\Program Files (x86)\scala . In batch files, variables in 'if' statements are expanded before the 'if' statement is parsed. The parenthesis confuses the parser
This problem will probably become more and more common as more people switch to new computers.