Error when running project on another machine

[RonVincent]

I've copied a Add-in from a 32-bit WinXP machine to a Vista 64-bit machine. When I try to run it from Visual Studio I receive the following error:

The ArcGISExplorer SDK is not correctly installed - 'ESRI.ArcGISExplorer.targets' not found (ArcGIS_E3SDK='').

I've tried doing a Repair and I've tried uninstalling the SDK and re-installing it without any luck. I think this has to do with the ArcGIS_E3SDK not pointing to the file ESRI.ArcGISExplorer.targets. This file exists under C:\Program Files (x86)\Explorer\bin but of course my Visual Studio solution was created under a 32-bit WinXP machine which points to C:\Program Files\Explorer\bin.

Anyone know where to update my project to the correct path?

Thanks.

[ShellyGill2]

Hi - I missed this post when you posted, sorry reply is rather late now but for the record: If you open your Environment Variables on the Vista machine, where does the ArcGIS_E3SDK variable point to? The add-in project will take the install location of the SDK from this environment variable - it should point to \DeveloperKit folder, e.g. on my 32 bit Win7 machine it is:
C:\Program Files\Explorer\DeveloperKit
The only paths stored in the add-in project itself are relative to this location - you can see this though by opening the project file in a text editor (or in VS, right-click the project and choose Unload Project, and then right-click again and choose Edit) - you'll see the environment variable used in the BeforeBuild build task:

<Target Name="BeforeBuild" Condition="!Exists('$(ArcGIS_E3SDK)\..\Bin\ESRI.ArcGISExplorer.targets')">
  <Error Text="The ArcGISExplorer SDK is not correctly installed -
    'ESRI.ArcGISExplorer.targets' not found (ArcGIS_E3SDK='$(ArcGIS_E3SDK)')." />
</Target>