I've used the javax.comm classes in normal situations and they worked fine (all ports could be detected, read/write were all ok) But when trying to use them in Servlets using Tomcat, no ports could be detected. Anyone knows what additional config need to be done? I've already copied javax.comm.properties to the jdk/lib, and even to tomcat/lib directories. win32com.dll has also been copied to the respective bin directories (Even tried system32) comm.jar on the respective lib directories too. any help appreciated, thanks!