The 'Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine

Question

I have installed the 'Microsoft Access Database Engine 2010 Redistributable' as described in the blog entry

http://danielcai.blogspot.com/2011/02/solution-run-jet-database-engine-on-64.html

and it works in my windows-forms application. I now want to add some unit-tests and when running the unit-test I get the above error. I have checked my references but can't seem to figure out why it works in the application and not in the unit-test.

I'm working in VS2010 on a windows 7 ultimate x64 installation.

Can someone please help me ?

Answer 1

The Target Platform is probably set to Any CPU, which means when you run it from VS or in your 64-bit Windows it will execute as 64-bit code (and use the 64-bit Jet driver). But a typical unit test runner is executing in 32-bit mode and all assemblies it loads will then execute in 32-bit mode (since your project target platform is Any, ie either 32 or 64 bit). And Windows 7 does not come with a 32-bit Jet driver by default.