Thank you so much, adambyte.
It's the first time I post anything and I must tell you, it's a fantastic feeling to realize that I'm not alone in this Mac OS X world.
As for my problem, I must admit that I'm no closer to solving it than I was before.
The fact that my system is in French (I'm from Montréal) does not help me to follow your instructions.
I did make a search for all things "sherlock" on my hard disks and all that popped up concerned Sherlock 1 and Sherlock 2. If, as you seem to imply (and which makes sense), Sherlock 3 is part of Jaguar, is there any possibility to find IT on the Jag installation disks and installing it without having to re-install the whole system?
Thank you in advance for your precious help. I really appreciate it.