Productivity
If you use your Windows 10 computer for word processing, checking emails, browsing the internet, and playing Solitaire, you should have no problem using 4GB of RAM. If you are performing all of these activities at once, however, you might experience a dip in performance.
Most budget PCs come with 4GB of RAM as a base option, but if you plan on keeping your machine for several years, then opting up to 8GB of RAM is the safer bet, even if you only use it for light duties.
Gaming
We're not talking about Solitaire — heavy PC gaming at acceptable performance levels requires a substantial amount of RAM. Using a few popular modern titles as references, it is evident that gamers should have at least 8GB of RAM — the recommended minimum amount for Fallout 4, No Man's Sky, and Star Wars Battlefront (which actually would prefer even more RAM at 16GB).
If you're a gamer and want to ensure you have enough RAM for some current titles and future titles, go with at least 16GB.
Game streaming
If you'd like to join the thousands who stream video of themselves playing games or other activities, go with at least 8GB of RAM but consider opting for 16GB depending on the game's requirements. Don't forget your PC has to deal with both running the game and streaming video to the internet at the same time.
for Windows 7 64 bit 2 GB of RAM is the minimum recommend amount .