I have an HP Pavilion 6830. This machine came with 64 MB SDRAM PC100 installed in it. I have 2 slots for memory. I currently have 128MB of RAM intalled in the machine. I remove both 64MB SDRAM PC100 sticks. When I try to add 1 stick of 256 MB SDRAM PC100 or PC133 the system does not reconize the RAM. I can have the 256MB stick installed along with 1 64MB stick and the system only reconizes the 1 64MB stick of RAM. Both slots are enabled and this is the correct RAM for the PC. Is there a jumper that needs to be set in order for my machine to reconize the 256MB of RAM? Do I need to try 2 sticks of 128MB SDRAM PC100? Any thoughts??