Learn Spanish (Latin America): Tendrías que usar un cortafuegos nuevo.

Cortafuegos (firewall) is a compound noun made of a verb (corta, meaning cuts or blocks) and a plural noun (fuegos, meaning fires). In Spanish, words formed this way keep the -s even in the singular form. You say un cortafuegos for one firewall and los cortafuegos for multiple.

Why use the conditional tendrías que instead of the present tense tienes que?

Using the conditional makes the phrase softer. While tienes que (you have to) sounds like a strict obligation or command, tendrías que (you would have to) sounds more like advice, a recommendation, or a hypothetical solution to an IT problem.

Could I say un nuevo cortafuegos instead of un cortafuegos nuevo?

Yes, but the meaning shifts slightly. Placing nuevo after the noun (un cortafuegos nuevo) emphasizes that the firewall is a brand-new product. Placing it before (un nuevo cortafuegos) just means it is a newly acquired firewall or a replacement for your old one, even if the software itself isn't a recent release.

How would I express the result of setting up this firewall using the state passive (estar + past participle) from this lesson?