1998 Mitsubishi Eclipse Help!

My alternater belt recently broke. It was replaced by a friend (he looked like he knew what he was doing). I drove it around the block after and it was fine. Then later I went to drive it, I turned on the defrost and it started making a weird noise. Almost like a screaching. I turned that off and started backing out. It then started making the screaching noise and the battery and brake light came on. The power steering was also out. This car has given me so many problems! Help! Thanks!