does .NET framewok installed

I need API which return boolean if .NET framework is installed on the machine or not.
This API should work from VC++ 6.

Can you please explain further. I'm not even sure what you mean.

I need to check if .NET framework is installed.
If it is installed i will load dll that use the .NET framework.

I see.....is there a chance that an environment variable is set, or a #define type defintion you can check?