Is this a OS or a Hardware problem ?

please advice im using a 64bit OS

What is that you see in the bios. 6gb or 4gb ?

May be the problem which you face is identical to this

[Solved] Windows 7 64-bit showing 4GB RAM instead of 6GB - config-customize - windows-7.

According to the above link one of your memory module might have gone bad. Try checking with one module at a time. But before that, if your BIOS shows 6gb then you can enable max memory through msconfig > BOOT > advanced options..

Checked in BIOS it shows 6Gb and the max memory option wont lemme go more than 6gb, 1 dimm at a time works fine and shows 2 gb, ,so its not ram at all

more than 6gb ?. M8 you are having only 6gb ram and why do you want to set it to more than what you have. Or you meant in msconfig you cant set it more than 4gb ?

im sorry i meant it wont let me set more than 4gb

May be i think you should change some settings in the OS to accept the full 6gb ram (which unfortunately i dont know). Since you say that your bios shows 6gb, its the O/s which doesnt recognise the full RAM. So i cant say that this is a restriction imposed under windows 7 64bit because the max memory recognised here is 192gb.

Check these:

1. Are the 3 DIMMS installed in the correct series of slots?
2. Check that the DIMMs are fully home and latched in the slots.
3. If the above are OK but the memory is still not recognised correctly, it is possible that either one of the DIMMs is faulty or some of the pins in one of the DIMM slots are misaligned so that the SPD data can be read but the DIMM will not operate.

Try these three in the order of precedence:

1.
press windows key + R (runs the 'run' dialog box)
type msconfig
go to boot tab
go to advanced settings
(here's where it's different)
UNTICK BOTH 'no. of processors' and 'max memory'

2. Reset BIOS to default.
3. Update to latest BIOS.

Let us know...!

Bios is upto date, now planning to put OC to stock and check

i tried the reset button on motherboard, but same issue


i put the BCLK value from 160 - 140 and now within OS its showing 6GB

can a basic overclock cause this kinda issue ?

^^
Ideally NO. Did you try the first point I had mentioned..?

1st point, msconfig is looking the way it should ideally be but now with bclk at 150 also its working fine, this was really wierd cos change of bclk cant alter memory amount, and its pretty ashtonishing