Often after installing more than 2 GB, users may notice not all of the memory is detected. The total memory supported by any 32-bit edition of Microsoft Windows is 4 GB.

Users who want more than 4 GB of total memory support in their computer must be running a computer with a 64-bit processor and operating system. Below is a listing of 64-bit memory limitations.

Why does BIOS detect more memory than Windows?

Some users may notice when they enter the BIOS/CMOS setup that their computer is detecting more memory in it than in Windows. BIOS relies on different drivers than those loaded by Windows, so this is not uncommon.

Your motherboard must also support more than 4 GB of memory.

  • See our memory definition for further information and related links.
  • Memory (RAM) help and support.