Just downloaded Windows 7. Why are some applications in Korean like ??^?? or all weird letters and signs?

I just downloaded Windows 7 today. So I downloaded AlZip(Korean) as my WinRar alternative. But because Alzip is Korean, Windows 7 shows all these weird signs and everything. A's with dots over their head, ? marks, 3/4 signs, Copyright signs, trademark signs, all these weird things. I tried changing the language, adding language, doing Unicode something, I don't know. Help me!