Your computer’s hardware and Windows 7 limit the amount of memory that your computer can use. In the case of 32-bit operating systems, that limit is 4GB of RAM. 64-bit operating systems can use much more. However, if your Windows 7 64-bit PC is having trouble recognizing all of the RAM in your computer, there is a quick fix that may work. Learn how to fix the maximum amount of RAM Windows 7 64-bit can use.

Windows 7 and Maximum Memory

Many users of the 32-bit version of Windows 7 were disappointed that not all of their 4GB of RAM (or more) could actually be used by the operating system. Many opted for the 64-bit version of Windows 7 but still had trouble getting the operating system to recognize and use all of the memory installed in the PC.

Typically, your computer’s hardware and Windows 7 works together to identify the hardware you have in your PC. This includes the memory or RAM you have installed. Occasionally, your computer is not aware of what you have and may report that you have less RAM than you actually do. Assuming this is not a hardware error or failure, there is one trick you can try.

Fix the Maximum Memory Windows 7 64-bit Can Address

The amount of memory you have installed in your PC is not necessarily the amount that Windows 7 64-bit can address. Address simply means use. Luckily, you can specify how much memory Windows 7 64-bit should address on boot up.

Log in to Windows 7 64-bit with an account that has administrative privileges. Click on Start and then right click on My Computer. Choose Properties from the menu.

Click on My Computer Properties

This opens the Properties window for your computer. In the section labeled System, note the amount of Installed Memory (RAM). Then, close the Properties window.

Find Amount of Installed Memory in Windows 7 64 bit

Click on Start and then on Run. If you don’t have the Run command on your Start menu, you can hold down the Windows key on your keyboard and press the R key. With the Run dialog box open, type in MSCONFIG and click the OK button.

Run MSCONFIG from the Run Command in Windows 7

This opens the System Configuration window. Click on the Boot tab and then click on the Advanced Options button.

Advanced Options in Windows 7 System Configuration

This opens the BOOT Advanced Options window. Click on the Maximum Memory option and type in the maximum amount of memory you noted earlier in the My Computer Properties window. When finished, click the OK button, close all remaining windows that you have opened, and restart your computer.

Change Maximum Memory Using Windows 7 BOOT Advanced Options

Windows 7 64-bit does not always correctly identify the amount of memory you have installed in your PC. You can fix this problem by manually specifying how much memory Windows 7 64-bit should use by changing a value in the BOOT Advanced Options window.

Assuming you have no hardware or software errors, Windows 7 should then be able to correctly identify how much memory you have installed and the maximum amount of memory to use at boot up.

Comments [0]

  1. I have an HP Envy with i7 core and I installed 16GB RAM, but it shows only 8gb. I went through the msconfig and set to max memory, but system still shows 8gb Usable only. If I reboot and go into BIOS, not change anything, and come out and reboot the system, on the System info screen is says "Installed Memory 16gb (8GB usable)." But, that disappears again on the next reboot and it will show "Installed memory 8Gb."

    What is wrong here?

  2. I think it is because you are using Windows 7 Home Premium 64-bit and that version won't recognize more than 8GB, I think.

  3. The Home Basic version of Windows 7 64-bit only supports 8 GB of RAM. Home Premium 64-bit supports 16 GB with Professional 64-bit and above supporting 192 GB. Home Basic is supposed to be for emerging markets. It's not available in most of North America, Western and Central Europe, and Australia. I suggest buying Home Premium or even Professional and using the Windows Anytime Upgrade.


  4. Sounds like you have either Windows 7 Starter or Windows 7 Home Basic, which have been artificially capped at 8GB.

    Windows 7 Home Premium is capped at 16GB, so if you have that version there is definitely something amiss with your installation somewhere.

    The memory caps for the various Windows 7 versions are stated and discussed here:

    Hope it helps. :)

  5. What if you set the max memory to 0? I goofed and left the max mem boxed checked with 0 in the field below and re-booted, now I can not get Windows to boot…. Is the only option to re-install Windows?

    Windows 7 x64

  6. So, I tried this and it would never accept any values close to 8,192 MB. In fact, most attempts of entering a number close to that resulted in it automatically reverting back to a number around 2,000 MB. When I finally typed a number higher, it went to 0 MB. Because I had tried so many other things, I for some reason, went with it… Now Windows won’t boot at all. Is there a file I can locate and edit that contains this information?

  7. Never mind my previous comment. I was able to reset that goof-up by booting up into Advanced Recover / Command Prompt and using:

    bcdedit /deletevalue {default} truncatememory
    bcdedit /set {default} truncatememory 0x100000000

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