Please post the full stack trace you get from the ant build. Also, you should add the -v option to the ant command line to get more information about the problem. I am not sure about the cause of the error dialog. It looks like a 16-bit app is being run at some point, but the 16-bit virtual device manager (ntvdm.exe) is having problems running (could be a faulty XP install). View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4159792#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...