Problem setting up 4 GB of ram

[rmdl51]

Hello!
I Upgrade my system last week, a new motherboard ASUS P4P800-E Deluxe, I upgraded because I want to use 4 sticks of 1 GB of memory that I bought some time ago, but right now my problem is that my system only shows 3.25GB of ram, I use same brand 1GB micron pc3200 DDR400, computer properties shows 3.25GB, the BIOS shows 3455MB of ram, I checked with a program every bank of memory (AIDA32) and shows 4 banks occupied with 1 GB each, I'm using windows XP Pro SP2 a pentium 4 HT 3.4Ghz, my previous MOBO was an ECS 848P and only had 2 banks with 1 GB each but no problem, this MOBO supports 4GB but I dont know why only shows 3.25, Could you please help me about this issue. Thank you!!

 

[RealBlackStuff]

Good that they are all the same brand.
Are they also identical in their properties? Same CAS, same number of chips, all ECC or all non-ECC?
Have you tried swapping them around?

 

[DonNagual]

Just did a bit of googling, and this is a very common problem for 32bit windows (XP) operating systems.

Various devices have used 'normally unused by memory' parts of the 32 bit address range for accelerated I/O for years, decades even. It is because now people have large amounts physical memory the range gets mapped to the devices for accelerated I/O, and thus can't be mapped to memory.

http://forumz.tomshardware.com/hardware/gig-mem-gig-mem-ftopict179467.html

EDIT: also found this on microsoft's website:
http://support.microsoft.com/kb/888137/en-us

 

[Rage_3K_Moiz]

U need the 64-bit version of Win XP but I think it isn't supported by ur processor. Just go with ur current one it won't cause any problems.