This has just been happening a few days now but my pc will mysteriously reboot by itself, doesnt show any error. This started happening a few days ago when I added an extra 512mb of ddr ram to my system. This is usually the case first when my system is booted first in the day. After that its fine for the duration that its on. Anyone have any ideas as it seems weird to be the memory cuz it continues to run fine after the initial boot up.