Mike,

>Im trying to install MM .Net 2.3 to a Windows Vista 64 bit OS. I can't install it due to the following error:
>
>"The installer has encountered an unexpected error installing this package. This may indicate a problem with this package. The error code is 2869"
>
>I have tried to turn off the UAC and restarting my computer then reinstalling it again but the same error occurs.
>I have also tried to create a batch file that calls the installer and run it as administrator but the error is still there

This should install properly on Vista-64...have you already installed Visual Studio 2008 on this computer?

Best Regards,