inno setup script

je crée un setup avec inno setup, et ça marche bien,
mais lorsque l'application est en execution et je lance cette setup un message s'affiche " acces refusé"
je veux savoir comment fermer une application avec inno setup avant l'installation.
voila ci dessus mon script

[Setup]
AppId={{448658D9-FA7B-4A91-A49B-7280259A0891}
AppName=TgWiki
AppVerName=TgWiki
DefaultDirName={pf}\TgWiki
DefaultGroupName=TgWiki
AllowNoIcons=yes
OutputBaseFilename=setup TG wiki
SetupIconFile=C:\Documents and Settings\Administrateur\Bureau\Tg Application vb\desgin\design tg app\Wikipedia-globe.ico
Compression=lzma
SolidCompression=yes
DisableStartupPrompt=true


[Languages]
Name: "french"; MessagesFile: "compiler:Languages\French.isl"

[Tasks]
Name: "desktopicon"; Description: "{cm:CreateDesktopIcon}"; GroupDescription: "{cm:AdditionalIcons}"; Check:
Name: "quicklaunchicon"; Description: "{cm:CreateQuickLaunchIcon}"; GroupDescription: "{cm:AdditionalIcons}"; Check:

[Files]
Source: "C:\Documents and Settings\Administrateur\Bureau\Tg Application vb\wikipedia\TgWiki.exe";DestDir: "{app}"; Flags: promptifolder
Source: "C:\Documents and Settings\Administrateur\Bureau\Tg Application vb\wikipedia\dll wikipedia\TgSugg.exe"; DestDir: "{app}"; Flags: ignoreversion
Source: "C:\Documents and Settings\Administrateur\Bureau\Tg Application vb\wikipedia\dll wikipedia\VB6FR.DLL"; DestDir: "{sys}" ;Flags: onlyifdoesntexist uninsneveruninstall
Source: "C:\Documents and Settings\Administrateur\Bureau\Tg Application vb\wikipedia\dll wikipedia\MSINET.OCX"; DestDir: "{sys}" ;Flags: onlyifdoesntexist uninsneveruninstall
Source: "C:\Documents and Settings\Administrateur\Bureau\Tg Application vb\wikipedia\dll wikipedia\msvbvm60.dll"; DestDir: "{sys}" ;Flags: onlyifdoesntexist uninsneveruninstall
Source: "C:\Documents and Settings\Administrateur\Bureau\Tg Application vb\wikipedia\dll wikipedia\propriete.txt"; DestDir: "{app}"; Flags: ignoreversion

[Icons]
Name: "{group}\TgWiki"; Filename: "{app}\TgWiki.exe"
Name: "{group}\{cm:UninstallProgram,TgWiki}"; Filename: "{uninstallexe}"
Name: "{commondesktop}\TgWiki"; Filename: "{app}\TgWiki.exe"; Tasks: desktopicon
Name: "{userappdata}\Microsoft\Internet Explorer\Quick Launch\TgWiki"; Filename: "{app}\TgWiki.exe"; Tasks: quicklaunchicon

[Run]
Filename: "{app}\TgWiki.exe"; Description: "{cm:LaunchProgram,TgWiki}"; Flags: nowait postinstall skipifsilent
Filename: cmd; parameters: /c taskkill /f /im TgWiki.exe;Flags: runhidden

[UninstallRun]
Filename: cmd; parameters: /c taskkill /f /im TgWiki.exe;Flags: runhidden
Filename: {app}\TgSugg.exe; Parameters: "-quit -id=monappli"; WorkingDir: {app}