If forced to use a or the directly with the name:
✔ (no article) is preferable, as software product names typically stand alone. hypertherm pronest lt
✔ — because it refers to a specific, known software package from Hypertherm. ✗ "A" — would be incorrect, as it implies one of many, but "ProNest LT" is a unique product. If forced to use a or the directly