Cannot upgrade RAM in the Gigabyte motherboard to 6GB

I have got a desktop system , in my system there is installed intel core 2 duo processor and my motherboard is of Gigabyte. In my mother board there are are 4 RAM slots , so I wish to fill all those 4 slots available in it . So I tried by mounting two 1GB RAM sticks and two 2Gb sticks , but however it freezes my system , as soon as I remove my RAM stick of even 1 GB and make it of 5GB then it makes the system up and running , what according to you can be the possible reason for this RAM failure is it because of the motherboard , please let me know as I am getting too much frustrated. I am waiting for your response .

Well you just said that you had installed 4 RAM sticks on all the 4 RAM slots in your Gigabyte motherboard and when you remove the 1GB RAM stick from there it leads into system restarts , so I will suggest you to run a RAM test on it. you can try on each individual RAM and then turn on the system and see if your system is booting up safely. According to your situation, it seems the RAM stick you had removed may be corrupted, so in case if you have just bought it , please try to get it replaced and get yourself and install a new one.

Yes it may also be possible that your RAM stick may be corrupted , but before installing this much RAM sticks in your system it is always recommended that you first test the compatibility of your Gigabyte mother board , because there are many such users who try to over utilize the capacity of the motherboard. It is quite possible that your motherboard supports only 4GB and you are attempting to install 6 GB in it. So check the compatibility of your motherboard.

Yes both the cases may be a valid reason that why your system is freezing after installing this much of RAM on your motherboard. But I have got one more reason for you , it is also possible that your RAM sticks may be from different makers or manufacturers , so this may seem a silly reason to you but this can be quite possible , so please check if they are from the same manufacturers or not.