I tried this right now and I found IA is case sensitive.
I.e., windbg -ia won't work, whereas windbg -IA will work.
Default folders: C:\Program Files (x86)\Windows Kits\10\Debuggers\x86 and C:\Program Files (x86)\Windows Kits\10\Debuggers\x64.
Therefore, if you installed windbg in its default folders, and after you opened an elevated command prompt, the command could be:
Tried on OS: Win10 STD x64 v1703 b15063.540 (i.e. updated)
Win7 x86 (professional):
:wave:
