oh my God what a silly bug :wtf: some hours later i find the solution :-D, there was an uninitialited variable char szFile[512]="";

Thanks, I handle WM_GETMINMAXINFO in CChildFrame::OnGetMinMaxInfo(MINMAXINFO FAR* lpMMI){ // TODO: ..... lpMMI->ptMinTrackSize.x = 200; lpMMI->ptMaxTrackSize.x = 500; } it works but now i have a problem :confused:, I size the window to the min pixel size I choose, all ok, but then I try to make the window bigger traking it the traking border of the window not appear. why this problem? I use XP.