Hi!
First, check the actual exported name from DLL. It may be decorated and
looking like "_squareIt@8". You can use "depends.exe" from Visual Studio tools.
Second, exported names are case-sensitive.
Next, make sure that declared types of parameters and return value are valid
and parameters passed "ByVal". Exported functions in Dll are differs not only
by name, but also by number and types of parameters.

Alexander.

>What I did was that I added a function after the DllMain function with the
>following declaration:
>extern "C" __declspec(dllexport) double squareIt(double d)
>{
>return (d*d);
>}

>After doing so I complied the Dll,and everything was fine.
>Then I added the compiled Dll into the system folder and the did the same as
>you have told me but I get the errors something like
>"No Entry Point for Dll Found" Or "Bad Dll function call".