Solution : https://service.sap.com/sap/support/notes/119724 (SAP Service marketplace login required)
Key words : 
~ftp/general/frontend/patches/rel31i/windows/win32/gn_z, hierarchy 'hkey_currentuser\software\sap\sessionmanager\settings', 'hkey_currentuser\software\sap\sessionmanager\settingscreate, 'sap ag\sessionmanager\settings', windows registry editor 'regedit, 'sap\sessionmanager\settings', 1i form sapservx, 'hkey_currentuser\software', additional key words, active session started
Related Notes : 
       
| 104438 | Session Manager: conversion of shortcuts | 
| 96885 | Downloading front end patches |