How To: Remove Windows 7 32bit 4GB Memory Limit

How To: Remove Windows 7 32bit 4GB Memory Limit

If you are running a 32 bit Windows 7 and have 4GB or more ram installed on your system, you might already know Windows kernel(in traditional 32bit program architecture) has blocked out a good chunk of the memory into “hardware reserved” and thereby limiting your ram anywhere from 2.75GB to 3.5GB depending on your motherboard and chipset.



Due to an architectural decision made long ago, if you have 4GB of physical RAM installed, Windows is only able to report a portion of the physical 4GB of RAM (ranges from ~2.75GB to 3.5GB depending on the devices installed, motherboard’s chipset & BIOS).

This behavior is due to “memory mapped IO reservations”. Those reservations overlay the physical address space and mask out those physical addresses so that they cannot be used for working memory. This is independent of the OS running on the machine.

Significant chunks of address space below 4GB (the highest address accessible via 32-bit) get reserved for use by system hardware:

  • BIOS – including ACPI and legacy video support
  • PCI bus including bridges etc.
  • PCI Express support will reserve at least 256MB, up to 768MB depending on graphics card installed memory

What this means is a typical system may see between ~256MB and 1GB of address space below 4GB reserved for hardware use that the OS cannot access. Intel chipset specs are pretty good at explaining what address ranges gets reserved by default and in some cases call out that 1.5GB is always reserved and thus inaccessible to Windows.

While many articles has been written to say that there is no way to remove this limitation, it is actually wrong. Here’s a hacked kernel from  a programmers group in Russia to correct the limitation. In fact this is a known problem according to Microsoft themselves as the special version of Windows Server 2003 Datacenter edition in 32bit supports up to 64GB of ram. Geoff Chappell, a software analyst commented on his article that 32bit editions of Vista all contain code for using physical memory above 4GB, it is just that Microsoft doesn’t license you to use that code.

So all you have to do now is download the file below, follow the instructions from unawave.de and you are done! The file might get detected as a trojan on some antivirus software, when that happens don’t panic as it is a false positive. Simply add the executable file to your antivirus exclusion list(or disable it temporarily) and you should be able to open the program fine.

  Windows 7 32bit 4GB Ram Patch (2.3 MiB, 11,484 hits)

Below are some images of my own system’s resource monitor and computer properties, I have been using the hack on both my home and office computers, so far there hasn’t been any issues. Gaming, photo editing, browsing and general applications work fine together, the extra RAM space does really shine in multi-tasking especially on some days when I have over 20 chrome windows(instances) with multiple extensions running.

*Click on thumbnails for full-size images.

  • http://blogdochicocezar.wordpress.com/2011/03/10/como-remover-do-windows-7-32bits-o-limite-de-memoria-de-4gb/ Como remover do Windows 7 32bits o Limite de memória de 4GB « Blog do Chico Cezar
  • Ace9006

    this is a trojan … common guys, cant you release something good without trying to plant trojans ?

  • http://www.howorks.com Laurent Ho

    It is not a Trojan, it gets detected as a Trojan by some antivirus simply because it changes windows critical files. It is a false positive. I have been using it for more than a year without any issues.

  • ilsun

    I don’t know if it works, last time I use something like this and my Windows get screwed up
    saying it can’t run something correctly, will this have some trouble like this?

  • Ms2santos

    I’ve tried to install (win7 32 bits – including as administrator), but I’ve recieved a message

    “Cannot create file “C:Users…AppDataLocal4GB_GER.exe”.Access Denied”.

    Anybody has a solution to solve the problem, so I will install the patch?

  • touchwood

    Dangerous Rubbish!!
    Explanation:
    32bit OS <> addresses 2^32 bytes only. This is exactly the 4GiB, and that is the barrier. There are techniques to avoid this barrier (such as PAE – Physical Address Extension, in other words paging of the memory). BUT (!!) this support has to be included both in kernel AND the applications to be usable. Most of the appliacations are PAE unaware, they are even NOT ABLE to use more than 2GiB of address space that is intended for the application (the rest is for the kernel).

    Simply said: Even if you will use this hacked kernel, the only change you will see is the memory size in the “system” control panel.

    And two things to mention:

    1. You have NO GUARANTEE, that this hacked kernel is free from rootkits. I would definitely NOT risk compromise my machine by such type of hacks. As soon as you boot such a hacked kernel, the (potential) rootkit gets undetectable.

    2. Please make sure you know the difference between terms “RAM size”, “Address space” and “windows addressing basics”

  • Elias1997

    I downloaded but when i tried to open it, it just don’t open

  • Sadam60

    i downloaded it and it work my system is much faster too

  • Windows Run On beer

    Have you ever installed and setup Windows Server 2003 R2 Enterprise Edition?

blog comments powered by Disqus
Premium Wordpress Themes