Silent Install will not work

Hi,

I tried a silent install over Windows package Publisher with the following command:

"C:\Program Files\Rhinoceros 5.0 (64-bit)\System\x64\rhiexec.exe" grasshopper_0.9.76.0.rhi /silent /admin

The Installation starts, but ignores the parameters.

Just the normal Installation Window with "Install Grasshopper for ..." is popping up.

I try several alternatives for the command line, but it doesn't work.
rhi in Parameters or in path, "" for both or one

Whats going wrong?

The whole XML-File:

<CustomUpdate>

<Action>

<ElementType>CustomUpdateElements.ExecutableElement</ElementType>

<PathToExecutable>C:\Program Files\Rhinoceros 5.0 (64-bit)\System\x64\rhiexec.exe</PathToExecutable>

<Parameters>grasshopper_0.9.76.0.rhi /silent /admin</Parameters>

<KillProcess>True</KillProcess>

<TimeBeforeKilling>10</TimeBeforeKilling>

</Action>

</CustomUpdate>

Khing