There are many websites dedicated to the Win32 API, each of which has its good and bad points. Most, however, do not provide a complete API list.
The Microsoft MSDN website is, in our opinion, difficult to use when you don't know what you're looking for. If you know the exact name of the API function you want, you can find excellent references to it on the MSDN site, including information and how-to articles. But finding a complete list of all Windows API functions is nearly impossible. The general consensus is that even Microsoft does not publish documentation for the entire API.
The following short list represents Internet-based resources that are worth a look:
MSDN: Search for "Win32 API" or the specific API function name:
Microsoft DLL Help Database:
MSDN: Win32 API declarations download:
The ALLAPI Network:
VBNet Visual Basic Developers Resource Centre:
The Access Web: