I'm attempting to perform an in-place upgrade of a legacy SharePoint 2007 server running Windows Server 2003 32-bit to Windows Server 2008 32-bit. Normally, I prefer clean installs, but this server has a lot of components including InfoPath forms created using Visual Studio 2003.

After I ran through the upgrade, I was able to restore much of the functionality of the SharePoint site, but when I try an open an InfoPath form used by the application running on this server I get the following error:

Error -2147209021: InfoPath cannot open a new form. The form cannot be opened. To fix this problem, contact the form designer. Form template: http://server1/RFD/Forms/template.xsn

Any ideas how to recover these InfoPath forms?  As I mentioned, I did an in-place OS upgrade so all the file paths and permissions should have remained intact.

Thanks!