Eu acho que você precisa verificar primeiro se o PC remoto está vivo, então tente se conectar a ele.
@echo off
REM Try for 3 seconds if remote PC is alive
ping 192.168.1.2 -n 2 -w 400 2>&1 >nul
IF %ERRORLEVEL% NEQ 0 goto OnExit
goto Success
:OnExit
echo 192.168.1.2 is down
goto End
:Success
echo Remote computer is alive. Checking if share is available...
IF EXIST \192.168.1.2\SharedFolder\ (
echo SharedFolder is available.
) ELSE (
echo SharedFolder is unavailable.
)
:End
REM pause