Windows runs but programs crash with 4Gb of RAM

[stenno]

Hey there all,

I know I've seen several threads similar to the problem I have, but nothing quite as specific... so;

I recently bought a new PC with the following H/W:
- ASUS P5E3 Deluxe
- INTEL Core 2 Duo 3.16GHz E8500 [ LGA775 - 6MB - 45nm - 1333MHz]
- 2x DDR3 2GB [2x1GB] DDR1333 (PC3-10666) - CORSAIR DHX [TWIN3X2048-1333C9DHX]
- ASUS Extreme N8800GTS/HTDP ( GeForce 8800GTS 512MB 2xDVI HDTV HDCP )
- SATA150 74GB - 10000 WESTERN DIGITAL RAPTOR (16MB) [WD740ADFD]
- English Windows XP PRO SP2b OEM

On the initial building and setting up of the computer, i had consistent issues with the windows installer program crashing. Upon testing the RAM sticks i found a pair were faulty and these were duly replaced. I installed windows with only one of the pair (2Gb) installed and everything works great.

Now tough, when I add the other pair, I get the same message as others in the system tab showing only 3.12Gb, also tho, and more importantly, as soon as I run any kind of program, the program crashes instantly and closes, but windows still runs... Could this be a motherboard issue? or have i overloked something? I MEMtested the RAM bars and they are all ok. Can anyone shed some light on this?

Thanks

 

[San Pedro]

Memtest for longer, I guess.

Also, you only have 32bit OS that's why you will not see all 4gb or RAM.