FYI: nothing shown above worked for me in Win7.
However, this DID finally work:
PAUSE 0<CON
This also did NOT work for 'timeout'.
Without it, it gets this:
ERROR: input redirection not supported,...
With it, it gets this:
ERROR: The handle is invalid.
In my case, this occurred after doing this:
start /WAIT cmd.exe /V:ON /k "set IEdir & pushd %IEdir% & cd & call "C:\Program Files\Internet Explorer\iexplore.exe" & set XsetRC1=!errorlevel! & set Xset & echo Xrc1=!XsetRC1! & popd & timeout /T 3 & EXIT !XsetRC1!"
where IE returns an RC=1 (what a KILL also gets).
However, doing the exact same for FireFox and Thunderbird:
start /WAIT cmd.exe /V:ON /k "set FFdir & pushd %FFdir% & cd & call "C:\FireFox\FireFox.exe" & set XsetRC1=!errorlevel! & set Xset & echo Xrc1=!XsetRC1! & popd & timeout /T 3 & EXIT !XsetRC1!"
where FF and TB returns an RC=0, 'timeout' DOES work properly.
Also note that PAUSE does NOT fail in Win10.