DirectShow in the Windows SDK. XAudio/Dsound in the DirectXSDK or you can just use a plain WaveIn/Out API to record the sound for you. Yes, you need sockets.

"Flash Media Server" is worth googling. It's fairly new. Neonlight

I found out the problem. I was doing something wrong in my code. Too much detail to explain here.

Have a look at WM_NCHITTEST and WM_NCMOUSEMOVE. Maybe you can handle then in your own functions and create a tooltip yourself. Don't try it, just do it! ;-)