I just reformatted my laptop. After I re-installing, I checked properties and it says 4GB RAM, 3GB usable. What happen to the other 1GB?
As already mentioned the "missing" memory is duo to the limited address space (2^32). Hardware memory always takes priority over system memory and therefor there is not enough addresses left for the full 4GB of RAM.
PAE is automatically enabled for 32bit Windows XP, Vista and 7 if it's supported!
Please stay away from any of the switches! They can do more harm then help.
The only way Windows will address more then 2GB to user application is by using the 4GT switch. The problem here is that it will limit the kernel memory to only 1GB. If you ever come in the position where the kernel needs more you will see your system getting unstable ~ probably even BSoD.
The only safe way to use it would be with the USERVA switch by setting a value between 2048-3072 (2GB - 3B). The problem here is ~there is no calculation or guideline what to set it to.
Last but not least ~ Windows will always use the paging file unless you completely disabled it (which you should never do because it is also used for memory dumps on crash).
Hello, only safe way windows can see 4 GB of ram is if you use a 64 bit operating system.
This can happen with old motherboards, This is normal if you are using a 32 bit version or the BIOS is incorrectly set (64 bits). (Memory Hole remapping). motherboard address limitation not a windows fault.
you cant use 4 gb of ram on 32 bit OS, you wil need 64bit OS.
windows will only show between 3Gb and 3.5Gb and wont be able to make use of the full amount RAM. possible you don't have memory remapping enabled in your bios:
Memory remapping can be enabled/disabled in your BIOS by going to the Advanced tab, and entering the Northbridge Configuration menu.
remember that a 32-bit OS can only recognize 4 GB, but you take about 0.5 GB for address space, and 0.5 - 1 GB for a graphics card, you are left with = 4 - 0.5 - 0.5 = 3 GB OR = 4 - 0.5 - 1 = 2.5 GB.
Enable 4GB of memory
Memory Limits for Windows Releases
256 MB of physical memory appears to be missing when 4 GB of memory is installed
go to run and type: msconfig then click on Boot then Click on advanced options and then Uncheck maximum memory. See if that will help you
Also try to update Bios or flash it with precautions
Unfortunately, the 32 bit Windows operating system is only capable of utilizing a little more an 3 GB of memory.