According to another [url http://forum.java.sun.com/thread.jspa?forumID=31&threadID=682630]thread[/url] your can get the 2.0 version with the following link: http://javashoplm.sun.com/ECom/docs/Welcome.jsp?StoreId=22&PartDetailId=7235-javacomm-2.0-spec-oth-JSpec&SiteId=JSC&TransactionId=noreg
A Windows port of javax.comm is not currently offered by Sun. Among the reasons the previous edition of javax.comm for Windows was EOLed are that the Windows platform itself changed in incompatible ways, and the Windows port of javax.comm depended on an EOL'ed version of the JVM.
The 2.0 windows port you may still find around at Sun's software download center may not be around long. You may want to to find it from another vendor, or check out the version at http://www.rxtx.org and help support that if it falls short, or consider working with the Open Source community on a Windows port if those don't do it.
So it is time to forget java on windows if I want to use any sort of usb serial port communication?
This becaues of the exception generated if the usb cable is disconnected. When the cable to the device (e.g. USB to serial adapter or similar) is disconnected the error message "WaitCommEvent: Error 5" is printed in the console window a infinite number of times. Unfortunately it does not seem to be possible to catch this exception and thus it is not possible to use java anymore.....