I attempted to make a Windows program using raw API before but I didnt get very far... I like to completely understand everything until I move on... I dont like grey areas...

After all this talk about how much you guys dont like MFC, has inspired me to give it another try... Although I will probably have lots of questions... if you dont mind answering them...

My first is about the WNDCLASSEX struct... and its cbClsExtra member....

It says in MSDN that it specifies the number of extra bytes to allocate following the window-class structure.

My question is why would you want to or need to do this?