If you have a backup, you can revert the [Script] section of nwtoolset.ini in a text editor.
If not, try this:
[Script]
FontName=Courier New
FontSize=10
Templates=scripttemplates
AutoCompile=1
ScriptEditorWidth=800
ScriptEditorHeight=580
ScriptEditorLeft=20
ScriptEditorTop=20
ScriptEditorSideWidth=299
ScriptEditorBottomHeight=170
ColorSelectedText=16777215
ColorSelectedBack=8323072
ColorText=0
ColorBack=16777215
ColorMargin=8355711
ColorComment=32512
ColorDirective=127
ColorIdentifier=0
ColorKeyword=16711680
ColorNumber=8323199
ColorString=8323072
ColorError=255
GenerateDebugInfo=0
ScriptEditorState=2