Thanks for your help Chown. I was on another mac forum also and he told me that some children or pets did that and he showed me how to fix it. Yes, it was my cat, she gets up here a lot.
Here is his reply:
No, you haven't been hacked. Somehow, the Macintosh HD icon was selected and renamed with miscellaneous characters. Sometimes people click it without knowing. Other times, pets or children tab combinations of keys on the keyboard and that is the result.
You can simply click once on the hard drive icon to select it, wait a second or two, then click once on those letters and it will change to editable mode. Then simply type in Macintosh HD or whatever your hard drive was titled and press Return.