The other methods here work if Internet Explorer isn't running.
If IE is already running though, it won't work properly. This is of course awful if a web page in IE is the starting vector for your script!
The fix I found is to use -noframemerging as a switch to iexplore.exe:
start "" /wait "%ProgramFiles%Internet Exploreriexplore.exe" -noframemerging "https://www.google.com"
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…