Messed Up My Friend's Computer

I did something I didn't mean to do. One day, I was over at my friend Casey's house, and they were working on their computer project for school. They were so engrossed in it that I thought if I could help, we could get it done faster. So, I started moving things around and installing some software tools that might speed up the work. In doing this, I must have accidentally deleted a folder or two. Casey found out later when they realized their project files were missing. They didn't say much about it to me directly, but ever since then, there's been an awkward silence between us. It was just supposed to be helpful, and now everything feels messed up.