RAM issue (RAM not showing up in Windows Task Manager) - Vista 64-bit

[alcoholbob]

When Windows Vista 64-bit loads the system info says 6.00GB of RAM installed. However, in Windows Task Manager, it says I only have 4GB of physical memory.

Is this a Windows issue, or is one of my RAM sticks going bad?

Also, when I turn on the DirectX Diagnostic Tool (dxdiag?) it shows I have 4GB of RAM.

 

[alcoholbob]

It's 3 sticks of 2GB of DDR3 1600 RAM on a Core i7 system.

 

[alcoholbob]

Here's an image link if this helps:

http://img134.imageshack.us/img134/2338/6or4.jpg

 

[taltamir]

3 x 2GB sticks showing up as 4gb? that means one isn't working...
one of them must be badly seated, check they are all all the way in.
if they are, then one might be defective. or it is the slot in the mobo that is defective

 

[Elixer]

Hmm. That is odd. You don't have a virtual ram drive do you?
Have you run memtest86+ yet?

Was this a clean install of vista, or a upgrade?