no viewers under windows

[Thomas Lozza]

hi
i downloaded version 1.3 for windows .. and it works.. but: under 
menu->layout i do not have any viewers (for pdf, ps, dvi) .. and i can 
only export to latex format... i thought that might have to do with the 
configuration of the reference file.. so i added some viewer entry... 
nothing happened..
anyone any ideas.. please.. ??