Windows: Press Win + I
Windows: Go to System > About
Windows: Open Task Manager with Ctrl + Shift + Esc
Windows: Check the Performance tab
Windows: Open Run with Win + R
Windows: Type dxdiag and press Enter
Windows: Open System Information by typing msinfo32 in Run
Windows: Open Device Manager from the Start menu
Mac: Click the Apple menu
Mac: Select About This Mac
Mac: Check the Overview tab
Mac: Open Activity Monitor
Mac: Open System Information from About This Mac
Linux: Open Terminal
Linux: Type lscpu
Linux: Type free -h
Linux: Type lsblk
Linux: Type inxi -F
Linux: Type neofetch
Check CPU model
Check RAM amount
Check storage type and capacity
Check GPU model
Check operating system version
Check motherboard details
Check screen resolution
Check network adapter details