.NET framework is copied to 'compiler/CLR' and 'GAC?

Question

The book of CLR via C# has this line at page 76.

When you install the .NET Framework, tow copies of Microsoft's assembly files are actuall installed. One set is installed into the compiler/CLR directory, and another set is installed into GAC subdirectory

I could find the GAC at C:\Windows\Microsoft.NET\assembly, but I couldn't find the compiler/CLR thing.

• What's the physical directory name of compiler/CLR? I mean, where is it?
• Why there are two GAC in assembly directory? I find GAC_32 and GAC_MSIL.

Answer 1

For framework 2.0 32 bit : C:\Windows\Microsoft.NET\Framework\v2.0.50727
For framework 2.0 64 bit : C:\Windows\Microsoft.NET\Framework64\v2.0.50727

GAC_MSIL is for assemblies in MSIL format, GAC_32 is for 'ngen'ed native assemblies in the x86 format. On a 64 bit machine you will also see GAC_64 folder which stores the AMD64 native images of assemblies.