My MBpro 15" was running really crappy the past week or so. Long story short, powered it off then upon restart I got the Question Mark Folder. I installed another hard drive from another identicle MPpro 15" and it powered up fine and went directly to the OS. Now, I just recieved the new hard drive and installed it just like the manual states and went to power the laptop on with the startup disk. I went to run disk utility and the new HD is not visible inside the window. Is this i sure fire sign the new HD is DOA, or am I just missing something? All of the tutorials I have found have stated the HD should be visible with a green arrow ready for partioning. Any help appreciated. FYI: The new HD is Western Digital 320GB 7200 RPM Black Scorpio or w/e they call it.