Compaq Visual Fortran v6.6 Professional doesn't Compile !!!

Hi all.
I'm an Sys Administrator at a University and I have a problema with Compaq Visual Fortran v6.6 Professional.
Under Administrator Account everythink is ok, but under Restricted Account it doesn't want to compile.
For example I want to make a Fortran Console Application (a "Hello World" sample project) and then when I want to compile it I recive such an error :

--------------------Configuration: Folder - Win32 Debug--------------------
Compiling Fortran...
Error spawning df.exe

say.obj - 1 error(s), 0 warning(s)

I tried to give write acc to the Folder where Fotran is installed in, then I gave write access to the User Profile
C:\Documents and Settings\user...but it didn't solve the problem.
Maybe I have to give write acc somewhere in the Regedit ?
I gave Full COntrol to this Key Name (and sub keys) => HKEY_LOCAL_MACHINE\SOFTWARE\DigitalEquipmentCorporation
& here
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio
..because I have installd Visual Studio 2005 too.

But still I get this error.
Please maybe somebody knows what to do !
10x in advance.