The document discusses the system requirements for Windows 7 and Windows 10. The requirements for both operating systems include a minimum 1 GHz processor, 1 GB RAM for 32-bit or 2 GB for 64-bit, and 16-20 GB of available hard disk space depending on the operating system. Both also require a DirectX 9 compatible graphics card with a WDDM 1.0 or higher driver.

2. System Requirements for Windows 7
 1 gigahertz (GHz) or faster 32-bit (x86) or 64-bit (x64)
processor*
 1 gigabyte (GB) RAM (32-bit) or 2 GB RAM (64-bit)
 16 GB available hard disk space (32-bit) or 20 GB (64-bit)
 DirectX 9 graphics device with WDDM 1.0 or higher driver

3. dxdiag
dxdiag is the abbreviation for the DirectX Diagnostics
Tool on all Windows operating systems. The DirectX
Diagnostics Tool provides detailed system information
including operating system version, graphics card
information, sound card and other hardware and
software information.

4. System Requirements for Windows
10
 Latest OS: Make sure you're running the latest version—
either Windows 7 SP1 or Windows 8.1 Update.
 Processor: 1 gigahertz (GHz) or faster processor or SoC
 RAM: 1 gigabyte (GB) for 32-bit or 2 GB for 64-bit
 Hard disk space: 16 GB for 32-bit OS or 20 GB for 64-bit
OS
 Graphics card: DirectX 9 or later with WDDM 1.0 driver

5. System Requirements for Windows
10
 Latest OS: Make sure you're running the latest version—
either Windows 7 SP1 or Windows 8.1 Update.
 Processor: 1 gigahertz (GHz) or faster processor or SoC
 RAM: 1 gigabyte (GB) for 32-bit or 2 GB for 64-bit
 Hard disk space: 16 GB for 32-bit OS or 20 GB for 64-bit
OS
 Graphics card: DirectX 9 or later with WDDM 1.0 driver

6. How to install Windows 7