After some ingenius cleaning, I optioned the trash can to be emptied. It didn't take long for me to realize what I had done, Finder told me it couldn't remove Terminal because it was being used....
I tried to reinstall Utilities with the Mac OS X(3.7) Install disk. But after double clicking the 'Install bundled software only' it would just open another Finder window.
How do I reinstall the Utilities?