IIS Express - increase memory limit

Go to Visual Studio - Tools - Options Menu

Choose: - Projects and Solutions, then Web Projects

tick the checkbox: "User the 64 bit version of IIS Express for web sites and projects"

No Registry edit necessary.

Both Cassini and IISExpress runs as 32 bit by default... You can configure Visual Studio 2012 to use IIS Express 64-bit by adding/setting the following registry key:

reg add HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\11.0\WebProjects /v Use64BitIISExpress /t REG_DWORD /d 1

IIS Express 8 and above supports both modes. Best to use an application like process explorer after making the registry change to inspect the IISExpress process and make sure that its running from the 64 bit location. When you install IIS 8.0 Express on a 64-bit system, both the 32-bit and 64-bit versions of IIS 8.0 Express will be installed respectively in the "%ProgramFiles(x86)%\IIS Express" and "%ProgramFiles%\IIS Express" folders.

Alternatively, you can install IIS locally and configure it to run your application. You can configure Visual Studio to point to a local instance of IIS.