XP Pro computer with 4 GB memory only showing 3.25GB, how can I get it to show 4gb?

Try scanning your system with the tools available to Crucial

http://www.crucial.com/uk/

http://www.crucial.com/uk/systemscanner/index.aspx

Good way of seeing what under the hood...

Upgrade to 64Bit.... Only way to get the rest of the RAM back.....

John6767 is absolutely right! In my case, there are no 64-bit drivers for my UMTS (3G mobile) card. ;)

The limitation of a 32bit OS is 4Gb, not 3.25GB !
Your OS shows 3.25GB because the upper part of address space is used for PCI devices and such.

Possible Solutions:

1) Install a 64-bit OS (both XP and Vista are available in 64bit), check your license if possible to change.

2) You have to look in your BIOS for an option called something like: "memory map above 4g" or similar. If option found and activated check your OS. If still no luck try PAE.
Since the Pentium pro and above, processors have supported PAE, that allows more then 4GB address space. You can enable this by putting the /PAE switch in boot.ini

Good Luck



 

PAE switch does not help, it's used on Enterprise editions of Windows OS. XP & Vista will not access 4 GB, no matter what you do. ;)

And EVERYBODY jumps in on this one.  Must be the second most popular question asked at Experts Exchange, behind "I forgot my password.  What do I do?" ...  ;0)

Thanks for all the answers, I would like to add that I have another Dell computer that is a Latitude D830 that I just upgraded from 2 to 4 GB of ram and its showing 3.5GB, its a 32bit system also with XP Pro, any comments?

Is there a top 10 list of questions on EE? I suggest that the following one takes 3rd place:
"My DNS does not work, it gives me "non-existant domain/server unknown"! ;)

Try to look for the "memory map above" option in BIOS, see what results this gives.

Congratulations, D830 apparently uses less RAM for address translations (different graphics card?). If anybody finds 32-bit OS which displays more than 3,54 GB (my personal record) I would appriciate a screenshoot from msinfo32 for my students. Check my profile for mail address.

This question seams to get asked on EE many times. Your computer is running normal. So I agree either upgrade to a 64 bit OS or live with the 3.25 GB it's reporting.

Just to confirm as a few others have said, 32-bit versions of Windows like Windows XP Pro (not the x64 version as thats a 64-bit version) are limited to 4GB of total addressable memory space.  Installed devices, built in devices and graphics memory will all impact what Windows "sees" as usable memory.

There is no switch, in software or the BIOS, that will "enable" the rest of your RAM.  If you must have 4GB from the OS view then you need a 64-bit operating system.  From all I've heard, you probably don't want XP x64 as there is very limited driver support for it but I hear Vista 64 is much better.  I still won't use Vista personally, at least not if I have a choice.

I hope I misread someones comment before, because I can't find it now, but no, this is not the result of a virus.

Thanks for all the great answers.