Thank you Averna,
I think I understand your theory, but a) after having installed Acrobat Reader the situation solves itself and no PDF opens up. b) that PDF is a national instrument PDF, definitely I don't have anything in the code that uses third party code other than the NI Labview 10 Professional VIs, if something like you are describing must be in a NI VI.
Also my installer is a very simple "exe" creator that links the top level VI and that's it
