JBoss Native 2.0.4 is the latest version, and yes it names the service JBAS50SVC in anticipation of the JBossAS 5.0 release, but I have used 2.0.4 with both AS 4.2.2 and 5.0.0.CR1 without any problems (it should work with 4.2.3 with no problems). One way to tell if you are running the 64-bit Windows is if you have both a Program Files and a Program Files(x86) directory. There are other ways also (and if I was at home where I am running 640bit Vista, I could tell you), most likely by looking the My Computer | Properties or at System Information. My guess would be that if you see a lot of x86 stuff, then you have a 64-bit system and the stuff you are looking at is compiled for 32-bit - the 64-bit Windows will run 32-bit software. Therefore, you can run a 32-bit JVM on 64-bit Windows, so that is not a clear indication of the OS type. Regardless of all that, you should ensure that the JBoss Native you are using matches the OS type - that is, if the OS is 64-bit, you need the 64-bit variation of JBoss Native. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4170448#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...