I tried to catch messages from a window that I can correctly find with EnumWindows/EnumChildWindows, and has the correct handle for it (I checked with WinSight32).
When I tried to get the WinProc of that window (it's classname is 'SysTreeView32') with GetWindowLong I get an error message of 'Access denied' - GetLastError gives back 5.
I can get the ClassWndProc without any error.
WinSight32 and Spy++ correctly gets the messages. I use WinXP professional as an OS and I logged in with an admin user. Where is the problem?
Thanx for the answers...