We have 6 iMac machines running Mac OSX 10.6 with multiple users in our Art Dept. Recently they have become very slow to log on to the user accounts set up on the machine - sometimes this takes 10 mins. I have inserted boot dosk and held down C key to boot from it but the process stops.
I was hoping to run some Utils and clean up the machines or even re-install the OS. I have also used Sophos to check for viruses and is clean. Not sure what to do next.