Once the Integrity is installed in one language say, English, is it possible to change the language to other language example Chinese without reinstalling it?
It's already a bit late, but in case you haven't found a solution yet: Yes, you can do that, however, it's, as far as I know, not an official solution:
You can open the installation directory and open the file "IntegrityClient.lax" from the bin folder in there. There's somewhere the property "lax.nl.java.option.additional", which also contains the Java VM argument "-Duser.language=de" (in my case), which is the language code of the language the client will be started in. If you change that to one of the otehr supported language keys and start the client, it should start with the newly selected language.
It worked for me. I am able to change the language to German but not in Chinese. I tried multiple times with different language codes. DO you have any idea?