The os seems to be blocking the execution of a setup executable for some reason (it does not appear in the task manager process list).

This is a fresh XP pro sp2 install, i already installed and can run several apps on it. I use /NoExecute=OptIn, but it looks like i m missing something...

I installed this setup on another machine with xp sp2 without any problem.

Any ideas?

Is it a downloaded file?
Maybe you have a corrupted install file.

Thanks for the answer Squirrel. I redownloaded the file, now it's working fine.