Some users have experienced the blue screen of death while installing Mac OS X Leopard. Installation goes fine until your Mac reboots, but then you are stuck with the blue screen, with your mouse pointer being the only thing working.

A cold restart doesn’t help either, you come back to the blue screen again. Some users have contacted Apple and have been told to wait for 2 – 3 hours and the installation will continue (oh, yeah right!), but this seems to be going nowhere.

The problem seems to be a process or an application that loads at start up and then hangs. In many cases, including myself, the application causing this problem is Application Enhancer (you had the Clear Dock installed, haven’t you?).

If you are reading this before upgrading your computer, go and remove the Clear Dock now. If you are already at the stage of pulling your hair – worry not, there is a bit of work to do, but it’s likely to be fine after that.


Reboot your Mac while holding Cmnd-S on your keyboard. Your computer will boot into the single user mode, no graphics, only the good old command line.

To modify files you need to type the following

/sbin/fsck -fy (then press return)
/sbin/mount -uw / (then press return again)

You can either go straight to their respective folders to delete these four files, or you can do it in one go by typing the following commands and pressing return on your keyboard after each line:

rm -rf /Library/Preference Panes/Application Enhancer.prefpane
rm -rf /Library/Frameworks/ApplicationEnhancer.framework
rm -rf /System/Library/SystemConfiguration/ApplicationEnhancer.bundle
rm -rf /Library/Preferences/com.unsanity.ape.plist

Now reboot your Mac from the installation DVD, open Disk Utility and repair the permissions. Reboot again, this time your Mac should boot into Leopard.