Question: Where is WinDbg.exe?
Answer:
Here is default location of WinDbg.exe when installed from Windows SDK.
64bit : C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\windbg.exe 32bit : C:\Program Files (x86)\Windows Kits\10\Debuggers\x86\windbg.exe
The folder above also has many other debugger tools such as cdb, kd, gflags, adplus, etc.