I'm running a 1.33 AthlonXP processor, Abit KG7 Socket A mobo and I was running (2)128Meg strips of Crucial DDR Ram. Two days ago I added in (1) 256Meg strip more of DDR ram (Kingston) for a total now of 512meg. All 512meg of RAM is shown as being recognized in Windows XP. Since adding additional RAM it seems that my computer will now be running fine then all of a sudden it's like someone hits the reset button...the darn thing restarts by itself. Tried putting a different Hard Drive in the machine and the same happens. Would anyone know what's is going on...didn't think adding RAM would cause such a problem...Thanks for any help.