 <p>you say you can't install anything, but could you write the necessary stuff into the registry yourself? I think that all regasm does is write all some stuff to the registry, so you could effectively do that from your VB code on startup if its not there and then you might be able to load the interop assembly.</p> <p>you can use a tool like <a href="http://technet.microsoft.com/en-us/sysinternals/bb896645.aspx" rel="nofollow noreferrer">process monitor</a> to see what gets written to the registry when you run regasm.</p> <p>I'd make sure you are using the -codebase switch and explicitly defining Guids for your interfaces and classes for the com wrappers as well. not doing so caused me no end of issues trying to get com wrapped .net dlls to work properly</p>