In this post I’ll show you how to configure your Visual Studio 2010 to step into the source code of .NET Framework 4.0 in 9 easy steps.

1. Download the 167Mb installer that contains the logic and data required to install Reference Source, .Net 4.0. On the download page table, its named “.Net”, Version: 4.
2. Execute the installer “Net_4.msi” that you have downloaded in the previous step.
3. Install it onto a path of your choice. Example “C:\Development\Framework 4 Source”
4. Launch Visual Studio 2010. From the Tools menu, choose Options and open the Debugging node.
5. Select General, then do the following:
   • Uncheck “Enable Just My Code (Managed only)”
   • Check “Enable source server support”
   • Uncheck “Require source files to exactly match the original version”
   • Optional: Uncheck “Step over properties and operators (Managed only)”
6. Select Symbols under Debugging.
7. In the Symbol File Locations box, add the downloaded symbols location: “C:\Development\Framework 4 Source\Symbols”
8. Enter in text box under ‘Cache symbols in this directory’: “C:\Development\Framework 4 Source\Symbols\Cache”
9. That’s it, you can now Step Into .NET source code. Happy sessions!