Windows is unable to find the "javaw" command in its environment path.
This can be resolved in two ways:
1) Set the PATH environment variable to include the full path to the Java release you'd like to utilize.
2) Fully qualify the path to java in the start command of the UCDJ.ini file. Example, replace the following:
cmd="javaw" -Xmx512m ...
cmd="C:\Program Files (x86)\Java\jre7\bin\javaw" -Xmx512m ...