A cleaner and better way to do this is with the usual console command:
FOR /D %a IN (c:\projects\repos\*) do git -C %~fa pull
or in a .bat file
FOR /D %%a IN (c:\projects\repos\*) do git -C %%~fa pull
PAUSE
Or even a .bat file in the project directory
FOR /D %%a IN (.\repos\*) do git -C %%~fa pull
PAUSE