Hi All. I am very new here. It took me all afternoon to find my way and I am still not sure I am in the right place.

I recently purchased an Inspiron 1420 with Vista with an Inspiron Core 2 duo and 3 gb ram.

When I asked a local seller about adding another gb, he said that it would slow things down, best left at 3 gb.  I searched the net and found everything from 512 mb to 16 gb reccommended. Is it necessary to match ie. 2-2 b sticks? If it is necessary to match, how come so many notebooks are sold with Vista  and 3 gb, a 2  gb stick and a 1 gb stick?

I am out of my depth when we get to hardware so would apreciate any information.

Thanks