I dragged my Firefox icon to the quickstart bar (or at least what I think is the quickstart bar. The bar on the far right which has a single 'Explorer' icon) and it apparently replaced firefox.exe with something else so Firefox no longer worked; it just brought up a DOS box briefly, then disappeared. Did a System Restore to restore Firefox.
I see now TOOLS > "Preview Document" brings up Firefox.
Is there a way to manually configure syntax color?