The two phases to the context of this discussion are listed follows.
Explanation:
<u>Solution 1</u>: Delete 1 GB of current RAM as well as install another DIMM0 Chan A slot through one 2 GB of double-channel RAM. (thinkable unless the 2 GB RAM is provided by the motherboard in what seems like a DIMM0 Chan A slot)
<u>Solution 2</u>: whether there's an unused or blank slot, perhaps one 1 GB dual-channel Ram could be mounted in some other slot at around the same speed or frequency.
It's quite safer to mount memory with appropriate frequencies across both situations.