On Jul 16, 2006, at 10:58 AM, eleventhvolume wrote: > ... Anyway, > having upgraded to 10.4.7... I typed reboot and depressed Apple/S to > enter single user mode to do fsck (the extent of my knowledge I'm > sorry to > say and probably mistaken at that), but didn't succeed so did > reboot again > and managed to get back into the normal OS. I repaired file > permissions via > disk utility until there was nothing being repaired and rebooted a > second > time. This time I got straight to my desktop. Boot from your install disc or another drive and run Disk Utility. Apple recommends DU (without explanation as far as I can tell) over fsck for Tiger. > [Deleted stuff] > I've rebooted again and now Disk Utility is displaying 'diskos1' > alongside > my normal Macintosh HD. Diskos1 is apparently not mounted, has a > partition > type of EFI and a capacity of 200mb. No other information's displayed. EFI is the new Intel boot firmware/BIOS. I haven't looked into boot camp, but if you have it installed maybe this is part of it? Anyway, after getting your disk to pass Disk Utility cleanly download the combo updater and redo the upgrade. If this fails then you may need to backup as best you can, reinstall from scratch, and then try Migration Assistant if you backed up the entire HD instead of just your data. Another possibility is to use something like Onyx to clean out all of the system caches. Phil