The 'Microsoft.Jet.OLEDB.4.0' provider is not registered on the local machine

I use two different machines for my automated testing. One is 64-bit Windows 7 and one is 32-bit Windows 7. Both run VS2010 Ultimate using an Access 2010 database for storing and retrieving the input data used by the scripts. My project (common to both machines) uses Provider .NET Framework Data Provider for OLE DB, so my database connection string is this...

Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\...

Never had any problem with either machine.

I had this same problem occur all of a sudden and it wasn't a "Jet" problem as it previously worked, and then stopped working. As it turned out, the application pool that the site was running under had "Enable 32-bit applications" changed to "False". When I changed back to "True", the OleDb error went away.

The Microsoft.Jet.OLEDB.4.0 provider is not registered on the local machine
Background

Amphis Customer is designed to work on 32 or 64 bit PCs running Windows XP, Windows Vista, Windows 7 or Windows 8 Pro, but on Windows XP 64 bit (and possibly other operating systems) it is possible that some of the Microsoft OLEDB DLLs have not been registered.

The Solution No. 1. :-p

The solution is to manually register those DLLs.

go to Start->Run and type cmd
this starts the Command Prompt
(also available from Start->Programs->Accessories->Command Prompt)

type cd .. and press return
type cd .. and press return again (keep doing this until the prompt shows :\> )

now you need to go to a special folder which might be c:\windows\system32 or it might be c:\winnt\system32 or it might be c:\windows\sysWOW64
try typing each of these eg
cd c:\windows\sysWOW64
(if it says The system cannot find the path specified, try the next one)
cd c:\windows\system32
cd c:\winnt\system32
when one of those doesn't cause an error, stop, you've found the correct folder.

now you need to register the OLE DB 4.0 DLLs by typing these commands and pressing return after each

regsvr32 Msjetoledb40.dll
regsvr32 Msjet40.dll
regsvr32 Mswstr10.dll
regsvr32 Msjter40.dll
regsvr32 Msjint40.dll

Solution No. 2 :p

To resolve this issue open the project in Visual Studio then:

1. From the solution explorer right-click your project then click Properties
2. Click the Build tab
3. Change Platform target from: Any CPU to x86
4. Re-build your solution

By Shishir Kumar
Research Nilman Team (RNT)

There is indeed no 64 bit version of Jet - and no plans (apparently) to produce one.

You might be able to use the ACE 64 bit driver: http://www.microsoft.com/en-us/download/details.aspx?displaylang=en&id=23734[^] - but I have no idea how that would work if you need to go back to Jet for your 32 bit apps.

However, you may be able to switch the project to 32bit in the Express version (I haven't tried and don't have 2008 installed in any flavour anymore) - there is a thread here that talks about it: http://xboxforums.create.msdn.com/forums/t/4377.aspx#22601[^]

Maybe it's time to scrap Access databases altogether, bite the bullet and go for SQL server instead?

ACE requires Access runtime engine, I think, whereas if a Jet solution can be contrived, there is no requirement to have Access present on the local machine, since Jet (used to) come with Windows.

Thus I would hope that Solutions 1 and 2 continue to work for a long, long time. If not, my solution road map will probably suffer great harm.

I don't know of anything that works with minimal licenses like Excel & Jet solutions, with ADO as the connectivity library and JRO as the database management library.

I am still looking, it seems critical to stay on top of this rather then get left for dead by MS.

Bill Benson

ENABLE 32 BIT TO TRUE IN APPLICATION POOL WILL DO..