This Acer 5742Z laptop, occasionally, constantly restarts or reboots. It not a overheating problem. Because it does it from a cold start. It boots to the Acer logo; shows the "F2 to setup" notice and then reboots. During this boot cycling, the F2 does not work. Somethimes it boots up normally. The cycle stops when I removed the DVD drive. So, I replaced the drive with a new one, without any change. It still continues to reboot. One note, sometimes, the laptop does not recognize the DVD drive. For, in My Computer, sometimes, the drive is not shown. I've already replaced the HDD and removed each of the memory chips, one at a time. No change. It doesn't appear to be a Windows issue. Because this happens before Windows loads. I am at a loss on what else to try. Could it be a Bios or motherboard issue? Any suggestions?