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.

Here's a quick explanation to why there is a need for hardware reserved memory.

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, 70,290 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.

Sausage

Hope this helps

This post has been edited by omgimahero: Apr 23 2013, 10:00 AM

wow.. but i still takut to try it

or the other solution is just jump to 64bit....worry not with 32bit compatibility issue
64bit windows can handle 32 bit software also...

agreed with him ^

Problem is eventhough Win 7 64bit does support 32bit application, but there are still some application that can't run on the 64bit platform even via compatibility mode. So this is a good workaround.

This kind of patch has been around for years already, and not every pc can use it, your pc will end up BSOD upon start up, because not every driver is compatible with this patch
unless the patch create secondary boot entry that boot into the unmodified windows system files.

I have tried but can't work for my laptop..

All 32-bit client versions of Windows (Vista/XP/7) have a 4GB "Address Space", not "RAM space". This is the theoretical upper limit and you cannot go beyond that.

You can't use entire 4GB of "Address Space". You can only use around 3GB of "RAM space" for OS. Because the rest of "Address Space" are reserved for hardware and not available to OS.

Total Address Space = Address Space for hardware + Address Space for RAM

Note that the hardware is using "Address Space", not the actual "RAM space" itself. Even you have a greater amount of RAM, the rest of "RAM space" goes unused because there is no enough "Address Space" to map on it.

This post has been edited by amazinggrace: May 11 2013, 04:17 PM