Thanks for your quick response! Unfortunately, it didn't help. The preview box is checked. The converter ist properly listed in the default file. However, since I'm not very familiar with Lyx/Latex and programming in general, it seems that I gave you only part of the full error message.
PreviewLoader::startLoading() Could not fork: Exec format error PreviewLoader::startLoading() Unable to start process C:\Programme\Office\Lyx\bin\lyxpreview2ppm.py C:/Data/Script/6lyxpreview.tex 129 ppm Could it be that the Windows vs. Unix convention of writing paths is the problem? I tried to execute the command manually in a shell and it didn't give me an error message with only Windows backslashes.
