Scripts .sh and .bat are very similar but installation is little bit different. For .sh you need to run ./postinstall that set up JBOSS_HOME variable in script. However, for .bat script u need to manually set up JBOSS_HOME variable to make it work or leave it to the script that set up JBOSS_HOME variable from working directory. Automatic set up of variable can cause problems to customer.

Suggestion - Make post install for windows, can be done by simply setting up JBOSS_HOME in postinstall file