I did as you suggested and no log was generated. But this time i went futher. I tried to install the service without the Install_LS_as_Service-NT.bat. I ran "mssn.exe install Lightstreamer" and in the diolog that opened I chose my wrapper.bat then started the service manualy and the Lightstreamer started successfully.

This is the Install_LS_as_Service-NT.bat
@echo off
setlocal

rem
rem NSSM Lightstreamer NT service install script
rem

if "%OS%"=="Windows_NT" goto nt
echo This script only works with NT-based versions of Windows.
goto :end

:nt

echo Attention Windows Vista and Windows 7 users, this
echo script must be run as Administrator.
echo Once the service is installed, do not move nssm*.exe files!
echo ...
echo Please check the output below
echo ...

rem Remove the service
if "%PROCESSOR_ARCHITECTURE%" == "AMD64" goto amd64nssm
goto x86nssm

:x86nssm
%0\..\nssm.exe install Lightstreamer %0\..\LS.bat run
goto :startserv

:amd64nssm
%0\..\nssm_x64.exe install Lightstreamer %0\..\LS.bat run
goto :startserv

:startserv
net start Lightstreamer

:end
pause