Question : Problem: "System32/DRIVERS/pci.sys"<wbr /> when I try to add RAM

I have attempted to add a 256MB stick to this notebook, bringing the RAM to 512MB, but keep getting the above error message.  I have tried inserting the stick in either slot and have tried 2 different brands of memory. HP says that I can bring up the RAM to 512 if I want. I have checked the Kingston and Crucial websites and I am attempting to add the correct RAM.
One of the sticks is a 256MB 144pin PC100 16chips 16x8 SDRAM SODIMM and the other brand edge,
256MB 144pin PC100 8chips 16x8 SDRAM SODIMM brand infineon. This last one didnt work either alone.
The OS is Windows SP Pro SP2

The machine is running with the present 256MB (first stick), but I wanted to increase RAM since XP hogs so much.  

Help!
carlos

Answer : Problem: "System32/DRIVERS/pci.sys"<wbr /> when I try to add RAM

It means neither stick works. Since you also got errors on the first stick that one is bad too. Sometimes it helps if you clean the slots and try reseating the sticks, then running the tests again.