Hi Lethier, It sounds lime your ram sticks are incompatible with each other. Most ram vendors recommend keeping your ram the same speed and make. here is a reference site; http://personal-computer-tutor.com/abc1/v2/ram.htm I hope this helps. Seasons Greetings ~ My Christmas card http://www3.telus.net/mikebike/mikesxmas_2002.htm Mike ~ It is a good day if I learned something new. Editor MikesWhatsNews see ~ http://www.mwn.ca <mikeswhatsnews-request@xxxxxxxxxxxxx?Subject=subscribe> See my Anti-Virus pages ~ http://virusinfo.hackfix.org A Technical Support Alliance Charter Member *********** REPLY SEPARATOR *********** On 21/12/2002 at 8:58 PM Lethier wrote: I am trying to upgrade RAM on a Toshiba Satellite 1800 series notebook. The RAM that the salesmen sold me was Azenram 128mb 133hz. My notebook has two slots and can be upgraded to 512mb. Currently, I have Samsung 128mb 100hz in slot 1. When I install the new RAM in slot 2 and keep the old RAM in slot 1, my notebook starts, the hard drive inidicator momentarily lights up, and then I get nothing (a dark screen). When I reverse the two RAM chips the same thing happens. However, when I use the new RAM chip alone in either slot, I experience no difficulties. I have updated my BIOS. What could be causing this problem? Thanks lethier - Users can unsubscribe from this list by sending email to 24hoursupport-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field OR by logging into the Web interface at http://webpages.charter.net/chizotz/