Hi Cameron, I've seen a similar error running on windows 7.
When you look in your datadir= specified in my.ini what is there exactly (hopefully not empty)? Do you have a mysql folder containing plugin.* files at this location? (say .MYI etc) It sounds like your data folders were either not copied to the correct place or not properly configured before starting the server. It's been a while, but I recall there being an "install" step to getting the correct basic database files into your datadir specified in my.ini. Good Luck, Robert Eby