Hi all,
This is more an informational post for anyone that might be experiencing this issue (and for myself incase I have the same problem in the future and can't remember the solution :-))
It's kind of obscure but caused me a few hours of stress, so maybe it'll help someone else... Sorry if this is repeated (couldn't find it) or deprecated (some don't have the luxury of latest and greatest).
If you are using trying to use Jet 4.0 to access MS Excel documents (or other data files) on a x64-based server, you will have discovered that there is no support for this combination.
The only solution is to allow IIS to run 32-bit applications on Windows 64 and to install a supported db provider:
Info - http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/13f991a5-45eb-496c-8618-2179c3753bb0.mspx?mfr=true
You'll need to install the driver, 64-Bit OLEDB Provider for ODBC (MSDASQL) that acts as a bridge:
"The Microsoft OLE DB Provider for ODBC (MSDASQL) is a technology that allows applications that are built on OLEDB and ADO (which uses OLEDB internally) to access data sources through an ODBC driver. MSDASQL is an OLEDB provider that connects to ODBC, instead of a database. MSDASQL ships with the Windows operating system, and Windows Server 2008 & Windows Vista SP1 are the first Windows releases to include a 64-bit version of the technology."
Download here : http://www.microsoft.com/downloads/details.aspx?FamilyID=000364db-5e8b-44a8-b9be-ca44d18b059b&displaylang=en
This all works fine, but I came across two things that had me scratching my head (and stressing):
1) You need to allow 32-bit ASP.Net in IIS Web Service Extensions - Read http://www.textcontrol.com/blog/permalink/2006082101/ for instructions on both enabling 32-bit apps AND the IIS web service extension setup.
2) If you are using any registry keys under IIS x64, a new node will be added in the registry - Wow6432Node - into which you'll need to move/copy any relevant keys that were used under x64.
i.e. We had a data key stored in HCLM\Software\CustomKey that was no longer available when 32-bit was enabled. We re-created the key under the Wow6432Node and all was good.
Sorry if I've waffled - hopefully the info is fairly succinct. Feel free to reply if you need more info.