Finally i succeed....the problem was : Client had MSI Version 2.0 (and need
3.1)
When i first tried to update MSI...i had an error on Cryptographic
service...(trouble with integrity of update.inf)

Here the solution (And then all my clients auto-updated to WSUS client)

1) run this :

:: Stop the Cryptographic service
%SystemRoot%\System32\net.exe stop CryptSvc
:: Rename all log files in the %SystemRoot%\Security folder
FOR %%a in (%SystemRoot%\Security\*.log) DO move /y %%a %%a.old
:: Rename the %SystemRoot%\System32\CatRoot2 folder
move /y %SystemRoot%\System32\CatRoot2 %SystemRoot%\System32\CatRoot2old
IF not exist %SystemRoot%\System32\CatRoot2 GOTO CONT01
:: In case the folder rename failed because of locked files
:: rename all log files in the %SystemRoot%\System32\CatRoot2 folder
FOR %%a in (%SystemRoot%\System32\CatRoot2\*.log) DO move /y %%a %%a.old
SET catroot2locked=True
:CONT01
:: Unregister DLL files that are associated with Cryptographic Services
CD /D %SystemRoot%\System32
start /wait regsvr32.exe /s /u softpub.dll
start /wait regsvr32.exe /s /u wintrust.dll
start /wait regsvr32.exe /s /u initpki.dll
start /wait regsvr32.exe /s /u dssenh.dll
start /wait regsvr32.exe /s /u rsaenh.dll
start /wait regsvr32.exe /s /u gpkcsp.dll
start /wait regsvr32.exe /s /u sccbase.dll
start /wait regsvr32.exe /s /u slbcsp.dll
start /wait regsvr32.exe /s /u cryptdlg.dll
:: Reregister DLL files that are associated with Cryptographic Services
start /wait regsvr32.exe /s softpub.dll
start /wait regsvr32.exe /s wintrust.dll
start /wait regsvr32.exe /s initpki.dll
start /wait regsvr32.exe /s dssenh.dll
start /wait regsvr32.exe /s rsaenh.dll
start /wait regsvr32.exe /s gpkcsp.dll
start /wait regsvr32.exe /s sccbase.dll
start /wait regsvr32.exe /s slbcsp.dll
start /wait regsvr32.exe /s cryptdlg.dll
:: Configure and start the Cryptographic service
%SystemRoot%\system32\sc.exe config CryptSvc start= auto
:: Start the Cryptographic Service
%SystemRoot%\system32\net.exe start CryptSvc

2) Then install MSI Installer 3.1 (WindowsInstaller-KB893803.exe)

3) Run this :

net stop wuauserv
REG DELETE
"HKLM\Software\Microsoft\Windows\CurrentVersion\Wi ndowsUpdate\Auto Update" /v
LastWaitTimeout /f
REG DELETE
"HKLM\Software\Microsoft\Windows\CurrentVersion\Wi ndowsUpdate\Auto Update" /v
DetectionStartTime /f
Reg Delete
"HKLM\Software\Microsoft\Windows\CurrentVersion\Wi ndowsUpdate\Auto Update" /v
NextDetectionTime /f
Reg Delete "HKLM\Software\Microsoft\Windows\CurrentVersion\Wi ndowsUpdate" /v
AccountDomainSid /f
Reg Delete "HKLM\Software\Microsoft\Windows\CurrentVersion\Wi ndowsUpdate" /v
PingID /f
net start wuauserv
wuauclt /resetauthorization /detectnow