Memory reporting wrong under Xp Pro/ Vista Ultimate

[kelvin45]

I am currently using 2 x 2 Gb of Kingston Hyper X memory.
If I put a single stick into slot 1 both the Bios and the OS reports the correct amount of memory.

If I place another stick into slot 2, the bios reports 4gb but Xp & vista report 2.5Gb.

The Mobo is a Gigabyte Ga-MA790X-DS4.

How do I get vista to report correct amount of memory, and am I actually losing 1.5Gb.


Kelvin

 

[Poolybit]

Couple of questions:

Are these 64 bit or 32 bit 'flavours' of Windows?

What graphics card have you got?