hwnd windbg extension
skywing aka ken johnsons's windbg extension sdbgext's command hwnd recompiled for x64
compile the src ( vs 2017 community )or use at your risk the precompiled hwnd.dll
copy hwnd.dll to windbg\winext directory .load hwnd.dll .chain to verify if it has loaded
!hwnd or !hwnd {specifc window handle}
0:000> !hwnd c045c Window 00000000000c045c Name "C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\windbg.exe" - WinDbg:10.0.17763.132 AMD64 Class WinDbgFrameClass WndProc 00007ff6a450ab00 Style WS_OVERLAPPED ExStyle WS_EX_WINDOWEDGE WS_EX_LEFT WS_EX_LTRREADING WS_EX_RIGHTSCROLLBAR HInstance 00007ff6a44e0000 ParentWnd 0000000000000000 Id 00000000069503f5 UserData 0000000000000000 Unicode TRUE ThreadId 00000000000017b8 ProcessId 0000000f00000d6c