using dll, assertion failed afxgetthread()

Well.. well..
Do you need to display window that interacts to user. And you need to control that from your Fortran program? Why is that?

If you just need MFC and to display some GUI, you can just use dialog (CDialog), and display controls in it. Write code to control window in CDialog's derived class.

But if you must display entire window (SDI), I would recommend you keep the MFC project as exe only. Further to that, implement some IPC to communicate from Fortran-process to MFC-process. Choosing IPC mechanism, out of mutex, pipes, mailslots, sockets, clipboard... all depends on your requirement.

SQL Server is an example. It displays everything with client process, but performs database operations in non-GUI service (sqlserver.exe).

Well calling the VC Application from Fortran is my instructors need.
And yes you got that right that i need VC++ Code only to present user with the GUI.So that user interacts with the dialog boxes and else stuff.
Regarding those mutex n pipes am totally unaware of these thing, but probably these things are similar to system call i guess?? so i cant pass parameters ato these if am correct....cant it be simple??
If I use VS.NET 2003 i have heard that i can call one project from other...is that true if you have any idea about that???

and yes is my method of starting the GUI correct??(by declaring the object of application class)

So, you want us to do you your homework?
I quit then!

hey its not an home-work its actually a MHRD project that I was designing but since I have to leave...am suppose to do so....so that later designing part can be done also fortran packages have to be used to solved those values that are entered by the user in GUI