'msbuild' is not recognized as an internal or external command, operable program or batch file.

Came across this question on google, not sure if anyone still needs an answer here, but i got it working.

To enable msbuild in Command Prompt, you simply have to add the path to the .net4 framework install on your machine to the PATH environment variable.

You can access the environment variables by right clicking on 'Computer', click 'properties' and click 'Advanced system settings' on the left navigation bar. On the next dialog bog click 'Environment variables,' scroll down to 'PATH' and edit it to include your path to the framework (don't forget a ';' after the last entry in here.

For reference my path was C:\Windows\Microsoft.NET\Framework\v4.0.30319.