Official specs from Steam

Halo: Reach system requirements

Minimum and recommended PC specs as listed by the developer on Steam.

Halo: Reach release infoSteam page Check other games

Minimum

OS *Windows 7
ProcessorAMD Phenom II X4 960T ; Intel i3550
Memory8 GB RAM
GraphicsAMD HD 6850 ; NVIDIA GeForce GTS 450
DirectXVersion 11
Storage25 GB available space
Additional NotesDirect3D feature Level 11.1

Recommended

OSWindows 10
ProcessorAMD FX-4100 ; Intel i7-870
Memory8 GB RAM
GraphicsAMD Radeon R7 360 ; NVIDIA GTX 560 TI
DirectXVersion 11
Storage25 GB available space
Additional NotesDirect3D feature Level 11.1

FAQ

What graphics card do I need for Halo: Reach?

Minimum: AMD HD 6850 ; NVIDIA GeForce GTS 450. Recommended: AMD Radeon R7 360 ; NVIDIA GTX 560 TI.

How much RAM does Halo: Reach need?

Halo: Reach needs 8 GB RAM at minimum, 8 GB RAM recommended.

How big is Halo: Reach?

Halo: Reach requires 25 GB available space.

Does Halo: Reach run on Mac or Steam Deck/Linux?

There is no native macOS version. There is no native Linux build (Proton compatibility may vary).