If you look at system requirements for a game, look at the type of things they list.
For example, from the GOG page for the game SOMA at
https://www.gog.com/game/soma Minimum system requirements - Windows: Windows 7 (64-bit) or later
Processor: Core i3 / AMD A6 2.4Ghz
Memory: 4 GB RAM
Graphics: NVIDIA GeForce GTX 260 / AMD Radeon HD 5750. OpenGL 3.3
Hard Drive: 25 GB available space
Additional Notes: Integrated Intel graphics are not supported. They should work (Intel HD 4000-series or better), but with issues.
Recommended system requirements - Windows: Windows 7 (64-bit) or later
Processor: Core i5 / AMD FX 2.4Ghz
Memory: 8 GB RAM
Graphics: NVIDIA GeForce GTX 480 / AMD Radeon HD 5970. OpenGL 3.3
Hard Drive: 25 GB available space
Additional Notes: Integrated Intel graphics are not supported. They should work (Intel HD 4000-series or better), but with issues.
So mostly what we need is:
Windows version (XP, Vista, Win7/8/8.1/10)
Processor
Memory (RAM)
Video card (graphics card or adaptor) (if possible the exact model rather than the "series")
Also good to know is....
Whether it's a laptop or notLaptop video cards tend to be less powerful than the desktop equivalent, and laptops that use Nvidia often use what's called "Optimus" graphics, which is actually an Nvidia chip on top of Intel graphics. Optimus causes problems with some games -- especially older implementations of Optimus.
We need to check that your computer meets the "Recommended" specs as well as the "Minimum" specs. If it meets "Minimum" but not "Recommended" you may be able to fix a problem by turning down game options (if the game offers them). We may also need to ask Google if there are known problems with the game using your particular video card.
IMO utilities like BelArc and speccy are easier to use than dxdiag.
For one thing, they're more apt to list your exact video card model than just the "series"
***screenshot of speccy***Speccy is from the makers of ccleaner
https://www.piriform.com/speccyInferno used to like the BelArc Advisor, and listed it under "Send Me Your Specs" as the utility to use to gather specs.
***Web Archive of Inferno's site***