Well when i bought my computer it came with 2 1gb ram cards installed and it was working perfectly. That was about a year ago and now the monitor had stopped working. when we take out 1 ram card doesnt matter which one or which slot it is in the monitor works again. We have tested the each individually and in each slot and the ram cards both work perfectly. But when we put both in at the same time it stops working.

The ram cards are PC2 6400 platinum editions

The graphics ard is Nvidia geforce 8800 GT

The motherboard is AMD Athalon 64 X2 dual

Also as a side not the mother board appears to have 4 slots for the ram cards 2 yello and 2 black. The yellow ones are where the ram cards were originally installed and the clips for the black ones are bigger than the yellow one's. When both ram cards are in the black slots the computer works but gets the blue screen of death every now and then and microsoft support said there might be hardware failure causing it. So i am pretty sure they dont belong in the black slots and when in the yellow slots the monitor doesn't work but they used to work in there.

Have you changed something in the BIOS settings ?

Actually yes i have, I returned it to default settings and when i pressed f10 to save and exit immediately after the monitor stopped working.

Any particular reason why you set the bios to default settings? I'm going to take a guess and say you have ocz platinum memory (ram). This memory although very good does require extra voltage to operate correctly. Setting the bios to default likely set the voltages to a lower level which makes the memory not function. If you can post what motherboard you have we might be able to help you a bit more. You might also want to check out the ocz forums for help to correct your issue http://www.ocztechnologyforum.com/

test the ram with memtest 86+ booted from a floppy or cd for 7 passes.

also read my ram guide in the guides forum

Ok you are exactly right and i returned it to defaults because i had a virus but didnt kniw it was a virus and it wouldnt let me use the computer so i was hoping returning to default would fix the problem but it didnt.

I have reformatted the computer so the virus is gone and i just need to fix the bios settings now.

I have an amd athalon 64 x2 dual cor processor 600+

I would be greatfull if you could tell me how to fix the power settings and if you know this would my processor be able to run windows vista 64 bit

You told us you can boot with one RAM. just boot in open the Bios settings change the voltage settings of the memory according to the datasheet provided by the producer (in this case ocx).

ok it says my ram uses 2.1v but when i go into the BIOS there is no option for changing ram or memory voltage. There is an option for DDR voltage if thats it. I just need to know what to change voltage for

Yes that is is .If as Tekkaraiden said the ocx needs more voltage than normal rams , then i guess you need to change the voltage to the one recommended by the Producer. how to do it ? well i guess you need to start some googling about that.

Ok i got it all up and working again thanks for the help.

I just have 1 more question what are the black slots for?

As a general rule, most boards run ram slots to fit most ram specs, the colour does not matter what so ever.

Take mine for example

2x yellow
2x orange

dual channel

i run two in the yellow and I will put another 2 in the orange, if your using two sticks and its dual channel dont mix colours, they need to be in same color but im sure you know that, that is the only reason they are color coded, unless your board is old mines quite new.