I use Snow Leopard. Recently I used Terminal to delete some swap files for space. I got a Terminal message saying swapfiles were low. I rebooted successfully. I then also deleted saveimages(?) through Terminal after which a few jpgs wouldn't open. A few gigs had been freed up. I also stupidly deleted one folder I couldn't ID which contained some files which said I didn't have permission to open but didn't ask for a password either. Now I can't move past the blue screen and Apple icon, even with safe mode. I tried one single user mode suggestion which failed. I started to boot from the CD but panicked when I realized I don't know if this will erase the hard drive (if it's not yet). I've never booted from CD and don't know if or how to fix it that way. I think I've made some terrible mistake. Help would be hugely appreciated.