Programming for Microsoft Windows® is really not hard—it's just a big subject, and you can't expect to know the entire subject after just a few hours of tinkering.
Any competent C programmer (someone with six months practical C experience) can learn to be a Windows programmer for in under a week. Start by reading the first three chapters of Programming Windows 3.1 by Charles Petzold (Microsoft Press®). (Petzold's book is also in the Development Library in full.) This tells you all you need to know about the architecture of a Windows-based application. Note: You need not implement any of the samples. This will take you less than a day.
Then get a copy of Microsoft Visual C++™ and go through the Scribble tutorial. This will take a day or two. Don't worry if you don't know C++. After completing the tutorial, you'll realize that C++ is very easy for a C programmer to pick up (at least the parts we need to build a simple Windows-based application).
Now test what you've learned by creating a simple Windows application for yourself. Don't try to write a game, a database, or any application that deals with the outside world (communications, printing, networking). Set yourself a simple task, such as an application that opens a text file and copies it to a window based on the CEditView class. If you can do this, you can write any application that needs to open a file and process the data within that file.