How to: Run a Unit Test as a 64-bit Process

If you have a 64-bit machine, you can run unit tests and capture code coverage information as a 64-bit process.

Running a unit test as a 64-bit process

If your code or tests were compiled as 32-bit/x86, but you now want to run them as a 64-bit process, recompile them as Any CPU, or optionally as 64-bit.

Tip

For maximum flexibility, you should compile your test projects with the Any CPU configuration. Then you can run on both 32 and 64 bit agents. There is no advantage to compiling test projects with the 64-bit configuration.
From the Visual Studio menu, choose Test, then choose Settings, and then choose Processor Architecture. Choose x64 to run the tests as a 64-bit process.

- or -

Specify <TargetPlatform>x64</TargetPlatform> in a .runsettings file. An advantage of this method is that you can specify groups of settings in different files and quickly switch between different settings. You can also copy settings between solutions. For more information, see Configuring Unit Tests by using a .runsettings File.