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How to Fix “8GB RAM Installed but Only 4GB Usable” Problem? Proven Methods for Reliable Results

By: Author Alex Lim

Posted on

Categories Troubleshooting

Why Does Windows Show 8GB RAM Installed but Only 4GB Usable? Effective Solutions Explained

When Windows displays 8GB of RAM installed but only 4GB as usable, it often signals a configuration or hardware issue. This guide provides clear, actionable steps to resolve the problem and ensure your system utilizes all available memory.

Common Causes and Solutions

Solution 1: Verify Windows Version (32-bit vs. 64-bit)

Windows 32-bit systems can only use up to 4GB of RAM. Upgrading to a 64-bit version allows access to more memory.

  1. Right-click the Start icon and select “Run.”
  2. Type msinfo32 and press Enter.
  3. Check “System Type.” If it says “x86-based PC,” you are running 32-bit Windows. Upgrade to 64-bit to use all RAM.

Solution 2: Test for Faulty RAM Sticks

Faulty RAM can prevent Windows from recognizing all installed memory.

  1. Power off your computer and remove one RAM stick.
  2. Boot the system and check if it detects the remaining RAM.
  3. Repeat with the other stick. Replace any defective modules.

Solution 3: Reseat RAM Sticks

Improperly seated RAM can lead to memory detection issues.

  1. Shut down and unplug your PC.
  2. Remove and carefully reinsert each RAM stick.
  3. Ensure each stick clicks firmly into place before reassembling and powering on.

Solution 4: Check Dual-Channel Mode

Single-channel operation or incorrect slot placement may limit usable RAM.

  1. Open Task Manager (Ctrl + Shift + Esc), go to the Performance tab, and select Memory.
  2. Check “Slots used.” If only one slot is active, consult your motherboard manual for optimal RAM placement to enable dual-channel mode.

Solution 5: Adjust BIOS Settings

BIOS configurations can restrict usable memory.

  1. Enter BIOS during startup (usually by pressing Del, F2, or Esc).
  2. Enable “Memory Remapping” if available.
  3. Set Virtualization to “On,” iGPU to “Off,” iGPU memory to “Auto,” and Render Stability to “Enabled.”

Solution 6: Update BIOS

Outdated BIOS may cause compatibility issues with RAM.

  1. Identify your motherboard or system model.
  2. Download the latest BIOS update from the manufacturer’s website.
  3. Follow the official instructions to update BIOS safely. Always back up your current BIOS before proceeding.

Quick Checklist

  • Confirm Windows is 64-bit.
  • Test each RAM stick individually.
  • Reseat RAM modules.
  • Ensure dual-channel mode is active if supported.
  • Enable memory remapping in BIOS.
  • Update BIOS to the latest version.

Addressing these factors typically resolves the “8GB RAM installed but only 4GB usable” issue, allowing your system to access its full memory capacity. These solutions empower users to resolve a common and frustrating hardware limitation, improving system performance and reliability.