Why do we get this type of error in Visual Studio unable to start projectname.exe

Hi,

Many of the times I have experienced in Visual Studio, that it compiles well, but problem comes during linking.
It says: unable to start C/…/ projectname.exe

I read here that it is a problem related to improper setting of environmental variable.

I followed the instructions given there but still I am facing the same problem. Please have a look at the attached screen shot, and help me in resolving this issue.

Thanks in advance.