What is the maximum RAM supported by Windows 10 Home?

Windows 10 Home supports a maximum of 128 GB of RAM on 64-bit systems. That limit is the edition's physical-memory ceiling, not a recommendation for how much memory every computer should have installed.

Windows 10 has different memory limits depending on both edition and processor architecture. The 32-bit version of Windows 10 Home is limited to 4 GB, while the 64-bit version can address up to 128 GB. Because 128 GB is the highest supported configuration for the edition, it is the canonical answer to this question.

The larger figures in the choices belong to higher-tier editions. Windows 10 Pro supports up to 2 TB on 64-bit systems, while Pro for Workstations and Enterprise support up to 6 TB. Another common mix-up is confusing the operating system limit with the motherboard limit: a PC may accept less RAM because of its firmware, chipset, or physical memory slots even when Windows supports more.