You don`t understand me And I don`t understand too A asked about disk, that caused problem... Now I understand you. How many DIMM you have now ? Usually MoBo supports only 3 unbuffered DIMM. And if you used 4 DIMM, I don`t know, what XP was changed in itself. I think, you must to use WindowsXP Recovery on the date before adding DIMM. Also, check the used virtual memory in default (if that chaneged). Maybe, uninstall the Power DVD (if you tell about videoDVD, check the videodriver). Also, MS has the utility for check videodecoder http://www.microsoft.com/downloads/details...&displaylang=en