How do I get TexForm to work on the command line? (Windows only)

try this?

 wolframscript -code HoldForm[1+1] -format TeXForm

 wolframscript -code Range@10 -format TeXForm

 wolframscript -c ConstantArray[0,{10,10}] -format TeXForm

if on Windows, the Command Line cmd should be run as Administrator to have wolframscript executed. get more info on how to use wolframscript under Windows by this way.