First post here and first attempt at a MacBook upgrade, so I was hoping I could get some advice. So I agreed to do a bit of work for a friend, but I'm usually a windows guy, so the things I'm encountering are new to me. It started off with my friend's Macbook not starting up, so I chucked in the Mac OS X disc to attempt repairing the OS. It didn't work due to the HDD being on it's last legs. I managed a backup of most of the important stuff, then tried reformatting the HDD, but didn't have any luck. In the end I decided just to grab them a new HDD. After replacing the old one, I thought it would be easy to just install OS X and be done with things, but i'm now have trouble with that too. It's a 1 TB HGST 7200rpm beauty that I picked up at wholesale, so I was pretty pleased with myself, but now i'm starting to wonder if I made a bad choice. When I put in the Mac OS X disc the HDD doesn't show up, so I thought I'd just reformat it to the extended (journaled) type, but when I try to do that I get an "Input Output Error". Plus I also noticed that it shows up as 7.3 TB? So I'm officially lost. Does anyone have thoughts on the matter? I'd really appreciate some advice.