well, the main purpose of all this is that I am working on a plugin for winamp that changes the status of Yahoo! Messenger v8 BETA and I need to get somehow the ID with which the user logged in. studying windows and messages with Spy++ did not help at all. And now that I heard about threats I said to myself that this must be the way to get the ID. The solution, in my mind, was this, to copy the memory into a buffer and seek the ID from the ones registered in Windows .