Hey there! Ok, so today I just upgraded my stock Macbook hard drive to a Seagate Momentus XT Hybrid 500GB 7200 RPM drive, and I upgraded the stock RAM to 8GB of DDR3 1333. After the upgrade, everything worked smoothly. And freaking screamed out frames on Wolfenstein and Devil May Cry 4 in Boot Camp! Barely dropped under 50 FPS on high settings. It was a beautiful thing When I quit Wolfenstein, and rebooted using the Windows menu, OSX was starting up normally. Then a grey progress bar loaded up and took about five minutes to fill. I should also mention that the Wolenstein disc was still in the drive when this happened, in case that's in any way relevant. I wondered what was wrong, so I restarted from the Apple Menu and got it again. And then a third time. So now I'm making a full backup onto my external drive. In case it's a failing hard drive like most of the stuff I found from googling and searching on here said it was, if the progress bar showed up numerous times. And I'm writing this question in the hope that someone highly competent answers. I really know my hardware stuff, I have my A+ certification for my job and a computer science and engineering degree from CMU i honestly barely use, this is just a problem I haven't ever encountered before. Could anyone shed some light on exactly why the bar is showing up for me, and how I can fix it?