I created the following error by making sure that I did not have the environment variable RCXTTY set properly. When it is not set, it defaults to trying to communicate on "com1", which is not correct when you are trying to communicate with the brick over a USB port.
C:\Java\lejos\bin>lejosfirmdl -f Use --help for options. segment.length = 13686 (14k) segment.length = 2938 (3k) Total image size=16624 (17k) RCXTTY undefined. Using: com1 C:\Java\lejos\bin\lejosfirmdl: tower not responding
This problem is corrected by setting the RCXTTY environment variable, as follows:
In fact, I go a step further, and I've created a batch file that sets three necessary variables in one step. My batch file looks as follows, and I run it once from a command (cmd) window before starting to work with the Lejos.
set JAVA_HOME=C:\j2sdk1.4.1_01 set LEJOS_HOME=C:\Java\lejos set RCXTTY=USB set CLASSPATH=.