I have a 6 month old iMac also with a Matshita drive. Its a different model from yours but I reckon it's a very noisy beast compared to my PC. It's rather ironic because the iMac is so quiet in operation compared to the PC, which has a couple of 20cm cooling fans that make it sound like a 747!
Generally speaking, Macs are not so customisable as PCs. My iMac case is sealed, like my iPod's, and there's no obvious way of opening. Doing so would invalidate my warranty in any case. Most Mac users I know have gone down the external drive route for expanding their systems.
To activate the Euro, use Alt 3.
Set up this - you may find it of use.
Keyboard Viewer and Character Palette- Open System Preferences (under Apple on the menu bar)
- On the Personal row, open International then go to the Input Menu tab and check whether Character Palette and Keyboard Viewer are ticked. If not tick.
- Down at the bottom of the window, tick Show input menu in menu bar.
That will display the Union Jack on the RH end of the menu bar near to the clock. (If you see the Stars & Strips, your international settings are wrong - change!)
Now when you require a special character like © or #, open Keyboard Viewer by clicking the Union Jack and selecting Show Keyboard Viewer. Press one of the keys on the bottom LH side of the Space Bar and watch what happens in Keyboard Viewer. Viola - keys change to show special symbols.
For additional info, read this.
Fred