Adding Ram. hi, my system configuration :

Question

hi, my system configuration : core 2 duo 1.8 ghz proccesor, 160 gb HDD, 1 GB ram with OS : Vista Ultimate.if i add another ram of 2GB Memory along with the existing ram will my pc get crashed? one of my friends said that using multiple rams is not advisble and he said that using 2 rams simultaneously will damage the ram..is this true.. kindly suggest ur option..