PC requirements

The Stanley Parable System Requirements

The Stanley Parable needs at least 3.0 GHz P4, Dual Core 2.0 (or higher) or AMD64X2 (or higher), 2 GB RAM and Video card must be 128 MB or more and should be a DirectX 9-compatible with support for Pixel Shader 2.0b (ATI Radeon X800 or higher / NVIDIA GeForce 7600 or higher / Intel HD Graphics 2000 or higher - *NOT* an Express graphics card). graphics.

Verified Sources: Steam store listing
The Stanley Parable minimum and recommended PC specifications
Component Minimum
Operating system Windows XP/Vista/7/8
Processor 3.0 GHz P4, Dual Core 2.0 (or higher) or AMD64X2 (or higher)
Memory 2 GB RAM
Graphics Video card must be 128 MB or more and should be a DirectX 9-compatible with support for Pixel Shader 2.0b (ATI Radeon X800 or higher / NVIDIA GeForce 7600 or higher / Intel HD Graphics 2000 or higher - *NOT* an Express graphics card).
Storage 3 GB available space
Additional notes DirectX 9.0c compatible
Not sure how your PC compares? Use the Can I Run It checker — pick your CPU and GPU and it tells you which column you land in.

Other platforms

The Stanley Parable is also available on these systems, where hardware is fixed and no per-PC check is needed:

Quick answers

Running The Stanley Parable on PC

Can my PC run The Stanley Parable?
Compare your CPU, GPU and RAM against the minimum column below. If your parts match or beat every minimum row, the game will launch — though you may need to lower settings. Matching the recommended column is what gets you 60fps at 1080p.
How much storage does The Stanley Parable need?
3 GB available space