I am trying to upgrade the memory from 512 to 1G. However, when I put in a 1G memory stick (or two 512m memory sticks), the computer will not boot. I put the old memory back in (which is currently 2 256m memory sticks), and flashed the BIOS thinking I needed to change a setting for the memory in there, but still nothing. I found that this PC does support 1G of memory yet I cannot get the PC to work with this much memory. Any thoughts?

http://h18000.www1.hp.com/products/quickspecs/11599_na/11599_na.HTML#Memory

Thanks, I have already tried the 2 512MB memory sticks as well, but that didn't work either.

Is the new memory single or double sided modules? If your laptop takes only single sided RAM and you bought double sided to upgrade it, then that's the problem. Also your board from the link jam posted only supports up to 1024MB (333MHz DDR-SDRAM) total memory or 2x512MB sticks. Computer Components

Thanks for the info. It is double sided, but so is the existing memory that is already in there, and that works. It seems like there is something else internally that needs to be upgraded (which is why I did the BIOS flash) in order for the new memory to be recognized. Very frustrating, as HP's troubleshooting website was completely useless.

http://www.crucial.com/store/listparts.asp?Mfr%2BProductline=HP+-+Compaq%2BHP+Business+Notebooks&mfr=HP+-+Compaq&tabid=AM&model=Business+Notebook+nx9010&submit=Go or http://tinyurl.com/lhwdr