I have a HP/Compaq NC6000 laptop that currently has 512mb of memory (512x1) and I want to upgrade to 1 gig or maybe even 2. Can I purchase a 1 gig stick and add it in conjunction with the 512 for 1.5 gig or do I have to have matched pairs? If so, I will purchase 1 gig for now and remove the 512 and then add the 2nd gig later on.

You should not need matched pairs.

Do you currently have only one stick or two? If you have one stick currently, I would pop it out, look at the sticker on the side of it (99% of them have an ID sticker), find out what speed and latency (CL) it is and try to find one that is comparable at Crucial.com using their memory selector.

If you have two sticks, you'll need to chuck em and get two new sticks.

Be sure that the system can support 1gig or even 2 gig of memory also.

the nc6000 is relatively new model and will support up to 2GB max of DDR333.

Thanks, I verified that also. I orded this http://www.simpletech.com/parts/sth389b1gb.htm

the nc6000 is relatively new model and will support up to 2GB max of DDR333.

Sweet

the nc6000 is relatively new model and will support up to 2GB max of DDR333.

Think I'll notice much difference between 1.5 & 2 gig? I think I will notice considerable improvement betwen 512 and 1.5 but not sure if 2 will be worth the extra $$$. As you know, my work laptop is loaded with tons of crap that I have no control over and I am certain that stuff is hogging a lot of resources.

i doubt it. i personally wouldn't mix a 1GB stick with a 512MB stick though. if you do, make sure the 1GB stick is in the primary slot (slot A, slot 1 maybe or slot 0)

i think in general with XP, you will notice a huge improvement from 128 to 256 upgrade, a considerable improvement from 256 to 512, a little bit improvement from 512 to 1GB (if you can notice it at all) and anything over that, chances are you're not going to see a difference unless you're working with large graphics or video files.