I keep rebooting even when holding C, even when trying 'startup disc'.
That is the easiest way to do it. Just connect an external USB or firewire drive, either clone your present system if it is healthy enough, or install the OS from a DVD, and copy the Disk Warrior application to the Application folder on the external drive.I cannot boot from the DiskWarrior 4.3 update disc either by holding C, by holding option (doesn't show up), nor by startup disc.
Something's up with the relationship between Snow Leopard and the version of OS on Disk Warrior.
Tech support was of no help; so I am looking at such workarounds as creating an external OS drive with Diskwarrior ON IT so I can boot from that.
Just to confirm, I have the same problem with the newest version of DW, 4.3, and an early 2009 iMac running 10.6.6. I'm about to install Snow Leopard on an external drive solely as a boot disk from which to run DW.
I too have had these problems. i've easily wasted 10 hours screwing around with the 4.3 DW trying to get it to boot up. Their tech 'help' have told me to; burn it to DVD instead of CD-R, don't use the bluetooth keyboard, but my old plugin kb, add a code into Terminal, and a hundred other things. It always says the 'disk is Locked' and will only Graph, never rebuild. I've tried to unlock everything and used Installer disk, etc. I've been pulling my hair out, I'm so disgusted. Of course, before Snow Leopard, everything always worked. I think Microsoft made Snow Leopard for apple, it's been so much trouble since I've installed it! I guess I'll try the Terminal code up here and also try the old 4.2 and see if it will work.
I still never got it to boot, but I didn't see the Option key trick until today. I'll try THAT next. I hate Snow Leopard. My Mac's have never been so messed since they introduced it.