Okay, the first thing I'll say is that I was running 10.6.7 when I tried to download, that might have been the problem. I thought I was up to date on Snow Leopard. This is what I did though: -Purchased Lion from App store -Started Download -Download bar shows that it's about 10% complete, a long way to go. Suddently it alerts me that the download is complete, which I couldn't believe. -Tried installation and it said that the file could be corrupted or tampered with and didn't work. -My thoughts: "Crap" -I then download 10.6.8, restart and retry to no avail. Here's what it looks like when I try now: http://www.youtube.com/watch?v=ZVBj9RCbEQg My questions: Will I have to purchase again to be able to re-download? How do I re-download off the app store? Input would be appreciated.