Compatable Compilers.

I Have A Few Diffrent Compilers for C++ Which one is compatable with the MMF Extension SDK?

Dev-C++ (Bloodshed software) - MinGW Compiler
Microsoft Visual C++ 6\2003

The extension SDK states "Visual C++ 6.0 or over", so the following should work :
Microsoft Visual C++ 6 <-- For sure (I use it)
Microsoft Visual C++ .NET 2002
Microsoft Visual C++ .NET 2003 <-- worked for neat_kliker2 in 1.5
Microsoft Visual C++ 2005 <-- pro worked for xinok in 1.5
Microsoft Visual C++ 2005 Express <-- Pretty certain. Plus, it is free!

I've not heard of it working with any non-MS compiler. In fact, I've heard that efforts to get MMF 1.5 extensions to compile in Ming32 and Borland have both failed.

Actually, there is a little bug with the Microsoft Visual C++ 2005 Express compiler. The "windows.h" header file doesnt load right, and it's a real hassle to try to fix it. I'd stick with one of the others, and try to avoid that bug <img src="/center/images/graemlins/tongue.gif" alt="" /> . That's just me, though.

[]Actually, there is a little bug with the Microsoft Visual C++ 2005 Express compiler. The "windows.h" header file doesnt load right, and it's a real hassle to try to fix it. I'd stick with one of the others, and try to avoid that bug <img src="/center/images/graemlins/tongue.gif" alt="" /> . That's just me, though. [/]
I've never had a problem with the Platform SDK in VC++ 2005 express. Are you sure the SDK was installed properly?