Assuming you have the foxpro runtimes installed (vfp9t.dll) and registered, the most common problem by far is directory locations and permissions. You should add a method to your server and have a simple Hello World type method that does nothing else but echo back environment settings like:

SYS(0)
CurDir()
SET(PATH)

etc.

to give you an idea exactly what state the server is in when your component is called.

This article is old, but still relevant and should help with trouble shooting:

http://www.west-wind.com/presentations/VfpDotNetInterop/aspcominterop.asp


+++ Rick ---
>Hi everyone
>
>We've created ou first dll com object and it works great on the development machine and another machine. We move it to a production machine and we get the message "Unspecified error" from the line where the ASP code is doing createobject. The user rights appear to be correct, but our thinking is we're missing something in the VFP required files. Could someone give us some direction of where to look. I'm not sure the error numbers will help, but this is what we get.
>Server object, ASP 0177 (0x80004005) unspecified error
>
>Thanks as usual
>Jon