Lot of numbers in that heading.
We've made the move to Windows 7 and we love it. However, we haven't really made the move to VB.NET. I still like developing in VB6; I know that makes me a little bit of a relic, but I don't do that much development these days to justify the investment in fully ramping up on VB.NET.
So, I had to tweak a legacy application I wrote which reads an email from a POP3 mailbox and writes the contents into a database. The program is maybe 30 lines long, and it's a dream thanks to the w3JMail library and ADO.
I revised the program, ran it on my Windows 7 machine, and all was right in the world. I went to deploy it back to the Windows 2003 server where it lives, and I was hit with Error 430 errors: "Class does not support Automation or does not support expected interface"
So, after adding line numbers to the code, I was able to track the error down to the line
Set objConn = New ADODB.Connection
That seemed weird. I tried a bunch of different ADO libraries and nothing. Then I stumbled upon a MSKB article, with the longest, most specific title I've seen in recent memory: "An ADO application does not run on down-level operating systems after you recompile it on a computer that is running Windows 7 SP 1 or Windows Server 2008 R2 SP 1 or that has KB983246 installed"
Long story short, if you're running Win7 SP1 or Win08R2 SP1, then .NET breaks ADO and you need to register some new type libraries on your local machine and then recompile using those type libraries, NOT the usual ADO libraries.
The KB article shows you how to do it easily enough. Put the files where they tell you. I had to manually navigate to the folders for some reason, but once I did, they registered up like a charm and my programs ran again.