How can i compile my blocks in simulink ?

i use it the command mex -setup see the list of available compilers i use the option of visual 2005, or 2008 , or 2010 and the windows says that they are not in they location but if have all installed it how can i do that case? i have matlab 2011b.

Also i have to say that i configured it in the pass and this week stop working, i´M using the Arduino IO blocks, just for general knowing.