I recently brought my old computer from the basement and loaded postal 1 up. It works fine, till I kill the first person. Then everyone including myself bursts into flames. Does anyone know why this happens and what I can I can do to fix it? Thanks

That shouldn't be happening if you're using the GOG version. That's their anti-piracy measure, like the unkillable scorpion thing in Serious Sam 3.

But the scorpion was fun. I wish there was an mod that could add the scorpion in Postal 1.