I am trying to open a program for the first time on Windows XP Pro that uses PostgreSQL 9. I'm getting an error message that says :
A problem was encountered while trying to log into or create the production database. Details: [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified
In my ODBC manager, I have a list of User DSN's and System DSN's. I tried installing a postgres odbc driver to see if that would help, but it didn't.
There is a connect.dat file in the program file with a line saying "OLE DB Provider = MSDASQL". Changing this entry alters the error message I get to "Provider cannot be found, it may not be properly installed".
I don't know what provider name to insert to get this to work properly. I have done extensive research on this error to no avail. Any suggestions would be greatly appreciated.
In reference to the error: [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified.
That error means that the Data Source Name (DSN) you are specifying in your connection configuration is not being found in the windows registry.
** It is important that your ODBC driver's executable and linking format (ELF) is the same as your application. In other words, you need a 32-bit driver for a 32-bit application or a 64-bit driver for a 64-bit application.
If these do not match, it is possible to configure a DSN for a 32-bit driver and when you attempt to use that DSN in a 64-bit application, the DSN won't be found because the registry holds DSN information in different places depending on ELF (32-bit versus 64-bit).
Be sure you are using the correct ODBC Administrator tool. On 32-bit and 64-bit Windows, the default ODBC Administrator tool is in c:\Windows\System32\odbcad32.exe. However, on a 64-bit Windows machine, the default is the 64-bit version. If you need to use the 32-bit ODBC Administrator tool on a 64-bit Windows system, you will need to run the one found here: C:\Windows\SysWOW64\odbcad32.exe
Where I see this tripping people up is when a user uses the default 64-bit ODBC Administrator to configure a DSN; thinking it is for a 32-bit DSN. Then when the 32-bit application attempts to connect using that DSN, "Data source not found..." occurs.
** It's also important to make sure the spelling of the DSN matches that of the configured DSN in the ODBC Administrator. One letter wrong is all it takes for a DSN to be mismatched.
Here is an article that may provide some additional details
It may not be the same product brand that you have, however; it is a generic problem that is encountered when using ODBC data source names.
In reference to the OLE DB Provider portion of your question, it appears to be a similar type of problem where the application is not able to locate the configuration for the specified provider.
Got this error because I had the Data Source Name in User DSN instead of System DSN 
The Problem might be from the driver name for example instead of DRIVER={MySQL ODBC 5.3 Driver} try DRIVER={MySQL ODBC 5.3 Unicode Driver} you can see the name of the driver from administration tool
I got this with data driven tests using:
Microsoft Excel Driver (*.xls, *.xlsx, *.xlsm, *.xlsb)
The problem is the above driver only is 32 bit. I had switched visual studio testsettings file to 64 bit to test a 64-bit-only application.
Switching back to 32 bit in the testsettings file fixed the issue.
using a test settings file
