In order for you to play Arma 3 on Windows with minimal graphics settings, your computer must meet the following requirements
OS:
Windows 7 SP1 (64bit)
Processor:
Intel Dual-Core 2.4 GHz or AMD Dual-Core Athlon 2.5 GHz
Memory:
4 GB RAM
Graphics:
NVIDIA GeForce 9800GT / AMD Radeon HD 5670 / Intel HD Graphics 4000 with 512 MB VRAM
DirectX®:
10
Hard Drive:
45 GB free space
Audio:
DirectX®-compatible on-board
In order to play Arma 3 on Windows with maximum graphics settings, you need a computer with a configuration no worse than the following
OS:
Windows 7 / 8 / 10 (64bit)
Processor:
Intel Core i5-4460 or AMD FX 4300 or better
Memory:
8 GB RAM
Graphics:
NVIDIA GeForce GTX 660 / AMD Radeon HD 7800 Series with 2 GB VRAM
DirectX®:
11
Hard Drive:
70 GB free space, SSD / Hybrid HDD / SSHD storage
Sound:
DirectX®-compatible soundcard