I'm currently running OSX Lion on my MacBook Pro, for a number of reasons including it generally just starting to run slow I'd like to format my hard disk and re-install Lion. From reading a number of guides on the web I should be able to do this by just backing up my precious data, doing Command-R at boot and choosing to re-install Lion, right? However, after choosing this last night and it downloading the install files I've been unsuccessful. When ever I now try and boot with Command-R it instantly says "There was a problem installing "Mac OS X" Try Reinstalling" but I have no idea where to get to any option to try reinstalling - I only have access to things like disk utility. I've attached the log below as a jpeg - as I can't copy and paste for obvious reasons. The key error seems to be "Bookmark failed to issue extension for item..." My basic need is to re-format and re-install Lion. Can anyone help either resolve the above issue or give me another approach? For example, if I used the Snow Leopard install disk to do this could I then just re-download and install Lion on top of that? Would I be charged for it again? Thanks in advance.