My machine started freezing and loading very slowly. I replaced the hard drive. Then it started this brief freeze and coding as if rebooting would begin, but then it would freeze. If I turned the laptop off then back on it would reboot and run for about an hour, then repeat the process. Thought the new drive was a dud and replaced it with a different brand. Instantly the process started again (didn't even get Snow Leopard updated enough for Lion this time). Thinking my baby is having a mother board issue instead of hard drive. Is this the correct thought or do I have a simplier, less deadly problem?
Pro, Mac OS X (10.7.3), randomly starts reboot then freeze