File or assembly name interop.Excel not found

[dpdg]

I've really been having a hard time with this one error message:

"File or assembly name interop.Excel or one of its dependencies not found"

It works fine on my computer with all the development software installed, but on some (not all) computers where the application is installed they get this error whenever they try to run it. It's anything that has to do with automating Excel. Ever since MS started pushing that interop business I've been having problems. And this company uses Excel big time so these modules HAVE to work.

The applications have been running fine with no problems for several years, but in the last couple of months I've been having nothing but problems.

On some computers I am able to manually install the interop dll's and the dependencies (Office XP PIAs), and they seem to work alright. But the computers that have a later version of the dot net framework installed it doesn't seem to help at all -- especially computers that have recently been re-OSed.

I don't know what to do, I'm about pulling my hair out and they are getting mad at me.

 

[jebenson]

Do the machines with problems actually have Excel installed?

Is yes, do they have the same version as on the development machine?

Can you install the older version(s) of the .NET Framework on these machines? (The different versions can coexist on the same machine with no problems.)



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[saikou]

dpdg - did you resolve this ?

I am having the same issue, been deploying applications using excel interop for years but now any new applications I develop produce the same error, can't even get a simple "hello world" to work on some machines (works fine on my dev machine and a few others).

Everything I do goes into the GAC.

 

[dpdg]

Yes. This did get resolved. The problem was that the version of the Office PIAs have to be the same version as the version of Office installed on the machine. That explains the reason that the application would run Excel automation on one machine and not on another.