Hi there,
Your CPU is below the recommended minimum, but the most likely reason is that your Windows 7 version is 32-bit instead of 64-bit.
I just looked up your CPU, and it is 64-bit OS capable, so installing a 64-bit OS could solve the problem for you. Only problem will be performance on that system, it will likely (if it will run at all) run very slowly. Upgrading your OS could potentially allow UE4 to run, but I can’t guarantee it.
I would recommend upgrading your PC to the minimum official requirements as follows:
- Desktop PC or Mac
- Windows 7 64-bit or Mac OS X 10.9.2 or later
- Quad-core Intel or AMD processor, 2.5 GHz or faster
- NVIDIA GeForce 470 GTX or AMD Radeon 6870 HD series card or higher
- 8 GB RAM
Hope that helps! 