Windows: Press Ctrl + Shift + Esc, open Task Manager, go to Performance > Memory
Windows: Open Command Prompt and run `wmic memorychip get capacity, speed, manufacturer, partnumber`
Windows: Open PowerShell and run `Get-CimInstance Win32_PhysicalMemory | Format-Table Manufacturer, PartNumber, Capacity, Speed`
Windows: Use System Information by running `msinfo32`
Mac: Click the Apple menu, choose About This Mac, then check Memory
Mac: Open System Information and select Memory
Linux: Run `free -h`
Linux: Run `sudo dmidecode -t memory`
Linux: Run `sudo lshw -short -C memory`
Check the RAM label on the physical memory stick
Check your computer or motherboard manual for supported and installed RAM details