A coworker has given me a spreadsheet that pulls data from an Oracle database.

He has no problem running the macro, but when I try to run it I get error
'429' ActiveX Component can't create object.

Here's the line that causes the error:
Set oOraSession = CreateObject("OracleInProcServer.XOraSession")

Can anyone suggest what my problem might be?

I'm pretty sure that I have an Oracle client installed on my PC, though I'm
not sure how to check that it's running.

Thanks,
Mike