Help! Blue Screen of Death after Hardware Upgrade

Hi, I'm new here. I have this random Blue Screen of Death (BSOD) appears on my one and it really freaks me out.

The Background:

I only got my one a week ago, the original spec was 1GB RAM, 120GB HDD, XP Home SP3.
I started messing around with it from the very first day. I did three upgrades at once, so apologise if I don't know where exactly the issue comes from.
I'm not much of a tech-pert but I'm quite an upgrade-geek, and most of the time I know what I’m doing. So I did the following upgrades:
1) Added in a Kingston KVR667D2S5/1G
2) Swap my 320GB Seagate external hdd with the 120GB that originally came with my one (it appears to be Seagate as well)
3) Install XP Pro SP3

The Issue:

My aspire one would randomly enters BSOD state with some error message about Memory Dumping, and it won’t turn off, I have to press and hold the power button and what I notice it seems to happen during power by battery or it’s just random thing, I’m not sure. Just trying t provide as much info as I can

Some Analysis done by me:
1) Now, I assume that XP Pro SP3 shouldn’t be a cause of that issue. (although it displaying it)
2) Not sure if this capacity of 320GB could cause that error but since it’s same brand with original one, shouldn’t be a problem? Or the bigger capacity requires some sort of more power usage that cause this kind of issue, I don’t know
3) I have seen some report Kingston KVR667D2S5/1G as unstable although, I’m not sure if that means system crashing like this?

Hope all the aspire tech-pert here could give me some suggestion?

 

I would install a different memory chip or run with out the kingston chip.

 

I figured it out!

the issue is not my ram,it's a kingston stick but it's the compatible one, it's the issue with my BIOS. I updatedBIOS wrong way i suppose, i usedthe GUI to flash it, i reflash it again using DOS and now it seems more stable. I've not seen the blue screen for the last two days(from what it was once or twice everyday)

thanks for the suggestion by the way