I have just downloaded and installed the VC++ 2010 Express tool from Microsoft.
I don't see an amd64 directory under c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\bin
In my old install of VC++ 2008 Express, there was an amd64 compiler, available in c:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\bin\amd64\cl.exe
Does the 2010 VC++ Express include an x64 or amd64 compiler?
No, but you can install the Platform SDK and switch the solution's SDK to Windows71 (instead of v100) to get x64 compilation working for free. The command-line compiler is only in the SDK.