I just downloaded and installed QT Creator 1.3.1 on my english Windows 7 system from the english download site at http://qt.nokia.com/downloads Apparently, however, the UI of QT Creator is in German language, although the help files are in English.
From the FAQ at http://www.qt.gitorious.org/qt-creator/pages/FrequentlyAskedQuestions I found the answer
Qt Creator uses the language setting of the system it runs on. On Linux systems you can also override that language by setting the LANG environment variable prior to starting Qt Creator, e.g. on the command line LANG=de ./qtcreator will run Qt Creator with german interface.
This, however, is apparently not correct, as I have an English Windows, and as system locale I have "English (United Kingdom)" set. Possibly QT Creator interprets mistakenly the Windows settings for "current location", which I have set to "Germany" to mean that German would also be my language. However, changing that value had apparently no effect (maybe it should have been done before installing QT Creator).
Is there any way to change the UI language of QT creator to english after installing it, preferrably without adjusting global system settings?