Windows detects 2.75 GB or no more than 4 GB of memory

Updated: 03/06/2020 by Computer Hope
Computer memory aka RAM

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.


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

64-bit OS Total memory
Windows 7 Ultimate/Enterprise/Professional 192 GB
Windows 7 Home Premium 19 GB
Windows 7 Home Basic 8 GB
Windows 7 Starter 2 GB
Windows Vista Ultimate/Enterprise/business 128 GB
Windows Vista Home Premium 16 GB
Windows Vista Home Basic 8 GB
Windows XP 64-bit 128 GB

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.