So a bought an older MacBook Air on the ebay recently. Out the box it was great, started up fine, transferred my data on migration app great, and it was a dream to carry to work. Well 3 weeks later bam, spinning circle at start-up, HD not able to be repaired, so I reformatted and let her rip again (using a store bought upgrade copy of Snow Leapord). Worked fine...for 3 days, now failing to start up again. Was able to get by with just a repair of the HD, but unable to recognize the disk when I tried to restart. 1) The HD is failing and needs to be replaced, correct? 2) What type of HD is recommended as a replacement? My main use will be traveling with this bad boy (by bike in sometime inclement weather if that makes a difference). Storage is not much of an issue as this is a second computer. 3) I replaced the HD on my Macbook pro (still working as I type on it) so I think I can do this. However, just moved to Copenhagen and am without computer tools (hoping not to do this again). So what will I need to get the job done easily and properly? 4) As I said I am in Copenhagen so if anyone can recommend places to buy hard drives online that ship to (or are based in) Europe that would be very helpful as well. On the bright side I still have this beauty, but too heavy) MacBook Pro to figure all this stuff out.