Add-on installation problem in Windows Server 2003

Hi guys,

I have a problem when i want to install my add-on in the Windows Server 2003. The server gives me error :

Unable to load AddOnInstallAPI.dll

and when i try install using the same installer at the client station, everything is ok.

Does anybody have suggestion about that problem? I suspect the problem is the Windows' security that did not allowed me to load the .dll. Does anybody know how to set the security?

Thanks you,

Harianto Ng