My MoBo has 3Gb RAM installed...

[Reilly]

My MoBo has 3Gb RAM installed but sees 1Gb, when i Put 2Gb it sees 2Gb but when i put 3Gb in it goes back to one.

DDR PC3200 (2x1Gb) 3x1Gb

Help

 

[stormy13]

Grab this,

CPUID - System & hardware benchmark, monitoring, reporting

and post a screen shot of the motherboard tab.

 

[richc46]

Take a known good stick and use it to test all the slots. If that works out try this test.
Guide to using Memtest86+
Test each stick for 6 passes.