I have a Dell XPS R400 with a Pentium II, 400 MHz processor running Windows 2000. (It originally had Windows 98). I currently have one socket filled with 128 MB of SDRAM (PC100, unbuffered, CL=2) . I would like to upgrade and add more memory. Information from Dell says the computer supports 100 Mhz SDRAM 168 pin DIMM with a maximum size of 128 MB up to a total of 384 MB (3 sockets). The motherboard is an Intel SE440BX-2. The documentation for it says it supports up to a 256 MB DIMM SDRAM for a total of 768 MB. Why the discrepancy? Is it based on the OS? And how high can I go?